webos: Initialize META_WEBOS_LAYER, META_OE_LAYER values

:Release Notes:
Set META_WEBOS_LAYER, META_OE_LAYER variables to build webos
outside of build-webos

:Detailed Notes:
For Yocto autobuilder to build webos-image without using build-webos
script. META_WEBOS_LAYER and META_OE_LAYER need to be set by hand.
These variables are used inside classes, recipes in meta-webos.
Initialize values in layer.conf, and the MCF script can override them.

:Testing Performed:
Only build tested

:QA Notes:
N/A

:Issues Addressed:
[WRQ-6441] CCC: Initialize META_WEBOS_LAYER, META_OE_LAYER values
[WRQ-6119] Consider dropping need for META_WEBOS_LAYER #28

Change-Id: Ic5abe4cb0eb09c2a0129daeb4f4f9ded2ecaa5a6

meta-webos/conf/layer.conf

@@ -31,6 +31,11 @@ BBFILES_DYNAMIC += " \
     clang-layer:${LAYERDIR}/dynamic-layers/clang-layer/*/*.bbappend \
 "
 
+# Set these variables to build webos outside of build-webos (for OSE only).
+# https://github.com/webosose/meta-webosose/issues/28
+META_WEBOS_LAYER ??= "${LAYERDIR}"
+META_OE_LAYER ??= "${@'${BBFILE_PATTERN_openembedded-layer}'[1:-1]}"
+
 # Prepend scripts to WEBOS_EXTRA_PATH
 WEBOS_EXTRA_PATH .= "${@'${BBFILE_PATTERN_meta-webos}'[1:] + 'scripts:'}"