inline kernel dtb build

also add sony device filter

Change-Id: Iffeda58c7086f49e76ecafd37941503611346983
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
merge changes from CyanogenMod 10.2 into local branch