qcom: Split off caf AUDIO_VARIANT support from QCOM_HARDWARE

One does not imply the other, add a different flag to allow using
them independently

Change-Id: I7fe0c0391967132a65f86f0c5f4bc0f54d50777d

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
Merge remote-tracking branch 'Slim/jb4.3' into slim4.3-test