meta-google: Cleanup for Yocto override syntax change

```
convert-overrides.py meta-google

git grep "_[a-z0-9_/-]*[ :]" -- meta-google | grep ".bb"

git grep -l _gbmc -- meta-google | grep ".bb" \
  | xargs sed -i 's/_gbmc/:gbmc/'
git grep -l _prod -- meta-google | grep ".bb" \
  | xargs sed -i 's/_prod/:prod/'
git grep -l _dev -- meta-google | grep ".bb" \
  | xargs sed -i 's/_dev/:dev/'
git grep -l _hoth -- meta-google | grep ".bb" \
  | xargs sed -i 's/_hoth/:hoth/'
git grep -l _bandaid -- meta-google | grep ".bb" \
  | xargs sed -i 's/_bandaid/:bandaid/'
```

Some small fix includes
```
platforms_gbmc_bringup
platforms_gbmc_secure
```

Tested:
```
$  git grep "_[a-z0-9_/-]*[ :]" -- meta-google | grep ".bb"
meta-google/recipes-connectivity/avahi/avahi_%.bbappend:do_install:append:gbmc() {
meta-google/recipes-core/dropbear/dropbear_%.bbappend:do_install:append:gbmc:dev() {
meta-google/recipes-core/dropbear/dropbear_%.bbappend:  echo '    chain gbmc_br_pub_input {' >>"$rules"
meta-google/recipes-extended/libconfig/conf2struct-native_git.bb:    oe_runmake checker
meta-google/recipes-extended/libconfig/conf2struct-native_git.bb:    oe_runmake install
meta-google/recipes-extended/networking/mstpd_git.bb:do_install:append() {
meta-google/recipes-extended/networking/sslh_git.bb:  oe_runmake distclean
meta-google/recipes-extended/networking/sslh_git.bb:  oe_runmake sslh-conf.h
meta-google/recipes-extended/networking/sslh_git.bb:  oe_runmake install
meta-google/recipes-google/ipmi/ipmi-fru-sh.bb:do_install:append() {
meta-google/recipes-google/ncsi/gbmc-ncsi-config.bb:do_install:append() {
meta-google/recipes-google/networking/gbmc-bridge.bb:do_rm_work:prepend() {
meta-google/recipes-google/networking/gbmc-bridge.bb:  # HACK: Work around broken do_rm_work not properly calling rm with `--`
meta-google/recipes-google/networking/gbmc-ip-monitor.bb:do_install:append() {
meta-google/recipes-google/networking/gbmc-iperf3.bb:do_install:append:dev() {
meta-google/recipes-google/networking/gbmc-iperf3.bb:  echo '    chain gbmc_br_pub_input {' >>"$rules"
meta-google/recipes-google/networking/gbmc-mac-config.bb:do_install:append() {
meta-google/recipes-google/networking/network-sh.bb:do_install:append() {
meta-google/recipes-google/ssh/authorized-keys-comp.bb:SUMMARY = "Compiles a set of authorized_keys files into a single file"
meta-google/recipes-google/ssh/authorized-keys-comp.bb:do_install:append() {
meta-google/recipes-google/systemd/gbmc-systemd-config.bb:do_install:append:dev() {
meta-google/recipes-google/test/test-sh.bb:do_install:append() {
meta-google/recipes-phosphor/flash/inplace-gbmc-update.bb:do_install:prepend:dev() {
meta-google/recipes-phosphor/host/phosphor-host-postd_%.bbappend:do_install:append:gbmc:dev() {
meta-google/recipes-phosphor/initrdscripts/obmc-phosphor-initfs.bbappend:do_install:append:gbmc:dev() {
meta-google/recipes-phosphor/initrdscripts/obmc-phosphor-initfs.bbappend:do_install:append:gbmc:prod() {
meta-google/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend:do_install:append:gbmc() {
meta-google/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend:  overlapping="$(jq '."${GBMCBR_IPMI_CHANNEL}" | .is_valid and .name != "gbmcbr"' $chjson)"
```

Change-Id: I9d610c664bd44e8bd81fb8f7e76249a0b43b9ffd
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/meta-google/recipes-google/ipmi/google-ipmi-i2c_git.bb b/meta-google/recipes-google/ipmi/google-ipmi-i2c_git.bb
index aeba2a9..3d5504e 100644
--- a/meta-google/recipes-google/ipmi/google-ipmi-i2c_git.bb
+++ b/meta-google/recipes-google/ipmi/google-ipmi-i2c_git.bb
@@ -16,9 +16,9 @@
 SRC_URI = "git://github.com/openbmc/google-ipmi-i2c"
 SRCREV = "b7d431199ac519e7c3cd5f3341d67f2ff0e09e10"
 
-FILES_${PN}_append = " ${libdir}/ipmid-providers/lib*${SOLIBS}"
-FILES_${PN}_append = " ${libdir}/host-ipmid/lib*${SOLIBS}"
-FILES_${PN}_append = " ${libdir}/net-ipmid/lib*${SOLIBS}"
-FILES_${PN}-dev_append = " ${libdir}/ipmid-providers/lib*${SOLIBSDEV} ${libdir}/ipmid-providers/*.la"
+FILES:${PN}:append = " ${libdir}/ipmid-providers/lib*${SOLIBS}"
+FILES:${PN}:append = " ${libdir}/host-ipmid/lib*${SOLIBS}"
+FILES:${PN}:append = " ${libdir}/net-ipmid/lib*${SOLIBS}"
+FILES:${PN}-dev:append = " ${libdir}/ipmid-providers/lib*${SOLIBSDEV} ${libdir}/ipmid-providers/*.la"
 
 HOSTIPMI_PROVIDER_LIBRARY += "libi2ccmds.so"
diff --git a/meta-google/recipes-google/ipmi/google-ipmi-sys_git.bb b/meta-google/recipes-google/ipmi/google-ipmi-sys_git.bb
index 801de43..1310f7e 100644
--- a/meta-google/recipes-google/ipmi/google-ipmi-sys_git.bb
+++ b/meta-google/recipes-google/ipmi/google-ipmi-sys_git.bb
@@ -21,15 +21,15 @@
 SRC_URI = "git://github.com/openbmc/google-ipmi-sys"
 SRCREV = "b69209b498bf9b1c009c528e40280d13e68f8dbd"
 
-FILES_${PN} += "${libdir}/ipmid-providers"
+FILES:${PN} += "${libdir}/ipmid-providers"
 
 SYSTEMD_PACKAGES = "${PN}"
-SYSTEMD_SERVICE_${PN} += " \
+SYSTEMD_SERVICE:${PN} += " \
   gbmc-host-poweroff.target \
   gbmc-psu-hardreset.target \
   "
 
 EXTRA_OEMESON += "-Dtests=disabled"
 
-CXXFLAGS_append_gbmc = '${@"" if not d.getVar("GBMC_NCSI_IF_NAME") else \
+CXXFLAGS:append:gbmc = '${@"" if not d.getVar("GBMC_NCSI_IF_NAME") else \
   " -DNCSI_IPMI_CHANNEL=1 -DNCSI_IF_NAME=" + d.getVar("GBMC_NCSI_IF_NAME")}'
diff --git a/meta-google/recipes-google/ipmi/ipmi-fru-sh.bb b/meta-google/recipes-google/ipmi/ipmi-fru-sh.bb
index deaee7a..881e623 100644
--- a/meta-google/recipes-google/ipmi/ipmi-fru-sh.bb
+++ b/meta-google/recipes-google/ipmi/ipmi-fru-sh.bb
@@ -3,14 +3,14 @@
 LICENSE = "Apache-2.0"
 LIC_FILES_CHKSUM = "file://${COREBASE}/meta/files/common-licenses/Apache-2.0;md5=89aea4e17d99a7cacdbeed46a0096b10"
 
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
 SRC_URI += "file://lib.sh"
 S = "${WORKDIR}"
 
 DATA = "${datadir}/ipmi-fru"
-FILES_${PN} += "${DATA}"
+FILES:${PN} += "${DATA}"
 
-do_install_append() {
+do_install:append() {
   install -d -m0755 ${D}${DATA}
   install -m0644 lib.sh ${D}${DATA}/
 }
diff --git a/meta-google/recipes-google/ipmi/metrics-ipmi-blobs_git.bb b/meta-google/recipes-google/ipmi/metrics-ipmi-blobs_git.bb
index 531d824..9437478 100644
--- a/meta-google/recipes-google/ipmi/metrics-ipmi-blobs_git.bb
+++ b/meta-google/recipes-google/ipmi/metrics-ipmi-blobs_git.bb
@@ -13,6 +13,6 @@
   protobuf \
   "
 
-FILES_${PN} += "${libdir}/blob-ipmid"
+FILES:${PN} += "${libdir}/blob-ipmid"
 
 EXTRA_OEMESON += "-Dtests=disabled"