audio: don't separate a2dp output and re-enable lpa

Change-Id: I951c86f43d34dc9bafaa846763349f42b9c2c8b4
d2: update hardware key overlays

Change-Id: I0bdf8b8d14796f54db7775e2bd89808e52253dd2
Merge remote-tracking branch 'upstream/cm-12.0' into cm-12.0