hal: Squashed collection of fixes

 * Remove unnecessary ifdefs for PCM offload
 * Remove unnecessary property for 24-bit support (use audio policy)
 * Clean up warnings

 * Also includes these patches from Google:

audio: fix set_parameters return value.

xxx_set_parameters functions were returning the status
returned by str_parms_create_str() which is incorrect.
These functions should return 0 when no error occurs.

Change-Id: Ib4a7ac427e49f5500c99902f86d2d69d5843eda0

Scan and verify audio device parameters on open

Scanning is default disabled at this time.
Verbose logs will display device params found.

Change-Id: Id188d096ec68d2058c66ae3a51fe57d9645d03ef
Signed-off-by: Andy Hung <hunga@google.com>

audio: deprecate audio_stream_frame_size()

Bug: 15000850.
Change-Id: I1bbe614c241befa24513a2b583594680e32fd954
hal: Support the audio amplifier hook

* Original legacy HAL commit:
  Ib236598a5888b2af19bcfb81e285f644a0e84c0d
* Example: http://review.cyanogenmod.org/38221

Change-Id: Ic944a9f7059c78b79322dae9c787cdd8bb029cff