libhardware: Add fix for offload playback.

-Offload mode requires frame size to be unity.
-Tunnel encode changes results in a invalid frame size being
 returned to audio flinger.
-Add 24 bit PCM format as exception to linear pcm.

Change-Id: I23d1960b0a493da20f48de788bb13e6f055ebe03
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_hardware_libhardware into temp