meta-inspur: Cleanup for Yocto override syntax change

Refer to: https://lore.kernel.org/openbmc/YQ1FD5q8KbhbXVBK@heinlein/

```
poky/scripts/contrib/convert-overrides.py meta-inspur

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

git grep -l _fp5280g2 -- meta-inspur | xargs sed -i \
's/_fp5280g2/:fp5280g2/'
git grep -l _on5263m5 -- meta-inspur | xargs sed -i \
's/_on5263m5/:on5263m5/'
git grep -l _virtual  -- meta-inspur | xargs sed -i \
's/_virtual/:virtual/'

```

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I5ef5039691caf5e33fb865da0fdd70d95d7e3bdf
diff --git a/meta-inspur/meta-fp5280g2/conf/local.conf.sample b/meta-inspur/meta-fp5280g2/conf/local.conf.sample
index 33fd6fd..e6decf4 100644
--- a/meta-inspur/meta-fp5280g2/conf/local.conf.sample
+++ b/meta-inspur/meta-fp5280g2/conf/local.conf.sample
@@ -1,11 +1,11 @@
 MACHINE ??= "fp5280g2"
 DISTRO ?= "openbmc-fp5280g2"
 PACKAGE_CLASSES ?= "package_rpm"
-SANITY_TESTED_DISTROS_append ?= " *"
-EXTRA_IMAGE_FEATURES = "debug-tweaks"
+SANITY_TESTED_DISTROS:append ?= " *"
+EXTRA_IMAGE_FEATURES ?= "debug-tweaks"
 USER_CLASSES ?= "buildstats image-prelink"
 PATCHRESOLVE = "noop"
-BB_DISKMON_DIRS = "\
+BB_DISKMON_DIRS ??= "\
     STOPTASKS,${TMPDIR},1G,100K \
     STOPTASKS,${DL_DIR},1G,100K \
     STOPTASKS,${SSTATE_DIR},1G,100K \
diff --git a/meta-inspur/meta-fp5280g2/conf/machine/fp5280g2.conf b/meta-inspur/meta-fp5280g2/conf/machine/fp5280g2.conf
index 8666375..50cee79 100644
--- a/meta-inspur/meta-fp5280g2/conf/machine/fp5280g2.conf
+++ b/meta-inspur/meta-fp5280g2/conf/machine/fp5280g2.conf
@@ -5,8 +5,8 @@
 
 OBMC_POWER_SUPPLY_INSTANCES = "0 1"
 
-PREFERRED_PROVIDER_virtual/openpower-fru-vpd-layout = "fp5280g2-openpower-fru-vpd-layout-native"
-PREFERRED_PROVIDER_virtual/openpower-fru-inventory = "fp5280g2-openpower-fru-inventory-native"
+PREFERRED_PROVIDER:virtual/openpower-fru-vpd-layout = "fp5280g2-openpower-fru-vpd-layout-native"
+PREFERRED_PROVIDER:virtual/openpower-fru-inventory = "fp5280g2-openpower-fru-inventory-native"
 
 require conf/machine/include/ast2500.inc
 require conf/machine/include/obmc-bsp-common.inc