audio policy: load audio hw modules

Audio hw modules are now loaded according to configuration
data read from audio_policy.conf. They are not loaded anymore
from a hardcoded list in AudiFlinger.

Output and input streams are opened on the hw module by which
they are exposed.

Also removed obsolete "acoustics" flags for input streams.

Change-Id: I8dc658cc83890d3ac7d5e36c372a03732aa5b0c4
5 files changed