Revert "audio: Only allow non-legacy HAL"

This reverts commit 5fe9117e1c48ab4dced5c1951f66b33936dcac4f.

Change-Id: I4b8eee51e4149b4d75b39958f5e152245f7247fe
hal: Add option to use low latency as primary output

 * Google's original design uses the low latency output as primary for
   playback unless a series of checks are passed in the framework which
   would use deep buffer mode.  Qualcomm changed this long ago in order
   for usecases like AV which don't require low latency to be forced to
   use deep buffering. This has been a catastrophic failure ever since
   it was changed, causing crackles and pops randomly while playing
   notifications due to underruns. Either I am too stupid to make it
   work, or this behavior is fundamentally flawed.
 * Add a flag to do it Google's way, I'm tired of this bug.

Revert "hal: Use deep buffer output as primary"

This reverts commit 8f715d94926ee51baf766800f4e9c3ceec435e4c.

Change-Id: I678478798274a35fe0d117650cfd62b1a433f448