meta-google: ipmi-config: Add option to remove default entity config

Currently it fources all gBMC to have `[]` as the entity-mapping config
and will cause an issue to gBMC systems that uses the default mapping.
Add a way to remove the default isntead of having all gBMC automatically
remove it.

ENTITY_MAPPING="default"
```
$ cat ./tmp/work/all-openbmc-linux/phosphor-ipmi-config/1.0-r1/package/usr/share/ipmi-providers/entity-map.json
[
    {
        "id": 0,
        "containerEntityId": 30,
        "containerEntityInstance": 0,
        "isList": false,
        "isLinked": false,
        "entities": [
            {
                "id": 11,
                "instance": 3
            },
            {
                "id": 11,
...
```

ENTITY_MAPPING="no"
```
$ cat ./tmp/work/all-openbmc-linux/phosphor-ipmi-config/1.0-r1/package/usr/share/ipmi-providers/entity-map.json
[]

```

Change-Id: I9adccc2685055bad8ac27207305083ba40327ce2
Signed-off-by: Willy Tu <wltu@google.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/meta-google/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend b/meta-google/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend
index aa2e266718..58997eedc1 100644
--- a/meta-google/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend
+++ b/meta-google/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend
@@ -6,6 +6,8 @@ DEPENDS:append:gbmc = " jq-native"
 
 GBMCBR_IPMI_CHANNEL ?= "11"
 
+ENTITY_MAPPING ?= "default"
+
 # Replace a channel in config.json to add gbmcbr reporting
 do_install:append:gbmc() {
   chjson=${D}${datadir}/ipmi-providers/channel_config.json
@@ -21,6 +23,8 @@ do_install:append:gbmc() {
 
   # Set entity-map.json to empty json for gBMC by default.
   # Each system will override it if needed.
-  echo "[]" > ${D}${datadir}/ipmi-providers/entity-map.json
+  if [[ "${ENTITY_MAPPING}" != "default" ]]; then
+    echo "[]" > ${D}${datadir}/ipmi-providers/entity-map.json
+  fi
 }