meta-quanta: meta-gbs: Cleanup for Yocto override syntax change

Cleanup with
```
convert-overrides.py meta-quanta/meta-gbs

git grep "_[a-z0-9_/-]*[ :]" -- meta-quanta/meta-gbs

git grep -l _gbs -- meta-quanta/meta-gbs \
  | xargs sed -i 's/_gbs/:gbs/'
```

After cleanup
```
$ git grep "_[a-z0-9_/-]*[ :]" -- meta-quanta/meta-gbs/ | grep '.bb'
meta-quanta/meta-gbs/recipes-bsp/images/npcm7xx-igps-native_%.bbappend:addtask do_gbs_prepare_xmls after do_patch before do_install
meta-quanta/meta-gbs/recipes-gbs/gbs-sysinit/gbs-sysinit.bb:do_install () {
meta-quanta/meta-gbs/recipes-google/acpi-power-state/acpi-power-state-daemon_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/fans/phosphor-pid-control_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/gpio/phosphor-gpio-monitor_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/interfaces/bmcweb_%.bbappend:do_install:append:gbs(){
meta-quanta/meta-gbs/recipes-phosphor/inventory/phosphor-inventory-manager_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/ipmi/phosphor-ipmi-blobs-binarystore_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/leds/phosphor-led-manager_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/sensors/phosphor-nvme_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-phosphor/sensors/phosphor-virtual-sensor_%.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-quanta/network/usb-network.bbappend:do_install:append:gbs() {
meta-quanta/meta-gbs/recipes-x86/chassis/x86-power-control_%.bbappend:do_install:append:gbs() {
```

Signed-off-by: Brandon Kim <brandonkim@google.com>
Change-Id: If640ddd3c6f6084bb0a1d82e2d18fa2640d9d83e
diff --git a/meta-quanta/meta-gbs/recipes-kernel/linux/linux-nuvoton_%.bbappend b/meta-quanta/meta-gbs/recipes-kernel/linux/linux-nuvoton_%.bbappend
index c2b5da4..85d0607 100644
--- a/meta-quanta/meta-gbs/recipes-kernel/linux/linux-nuvoton_%.bbappend
+++ b/meta-quanta/meta-gbs/recipes-kernel/linux/linux-nuvoton_%.bbappend
@@ -1,2 +1,2 @@
-FILESEXTRAPATHS_prepend_gbs := "${THISDIR}/linux-nuvoton:"
-SRC_URI_append_gbs = " file://gbs.cfg"
+FILESEXTRAPATHS:prepend:gbs := "${THISDIR}/linux-nuvoton:"
+SRC_URI:append:gbs = " file://gbs.cfg"