audio HAL: reverse mutex locking order

Do not use main audio HAL mutex but a specific stream mutex when
preventing control thread starvation by playback or capture threads.
This will prevent systematic locking of main HAL mutex in read ot write
and avoid glitches.

Bug: 21880828.
Bug: 18489202.

Change-Id: I3054e0d93b823bd9d2fb84a49e9c5bbbe728262a
1 file changed