audio-caf: allow devices to only set min buffer sizes

Required for Sony MSM8960 devices.

This is a port of codeworkx's patch from the mako audio repo.
x
alsa: make pcm debug flag optional

Change-Id: Iac2e017eab7ddf5300147cbdec7691a2cd00ff72
msm8660: Add dependency on kernel headers

 * Let's get rid of headers in device repositories.

Change-Id: I6408a1368cc1e3cd2f11d80f7eed54085dcd60c0
Merge remote-tracking branch 'cm/cm-10.1' into cm-10.1