am a9024def: audio: implement mute on hdmi multichannel

* commit 'a9024defa11f6502ca55425a4803cd00441d51e7':
  audio: implement mute on hdmi multichannel
tree: 9a0964994cd894316b196b59fa238c247fd4400a
  1. hal/
  2. legacy/
  3. Android.mk