inline kernel dtb build

also add sony device filter

Change-Id: Iffeda58c7086f49e76ecafd37941503611346983
Fix exporting the unique build identifier

Change-Id: Ie58e981b7e83a4351d137dfd8995dce7d365d950
Merge "inline kernel dtb build" into cm-10.2
build: Prevent some auto-generated variables from being overridden

These variables are used by internal processes for build indexing
and identification, and those processes expect either specific patterns,
or uniqueness.
So prevent accidental overriding of these by device configurations:
BUILD_DISPLAY_ID, BUILD_NUMBER, PLATFORM_VERSION, PLATFORM_SDK_VERSION,
PLATFORM_VERSION_CODENAME, BUILD_VERSION_TAGS

Change-Id: I06252f2687a5e5fd97ee21a98f26c739fd0ef6e4