Audio: 8916 Audio HAL bringup changes

-Separate platform specific code from generic audio HAL code

-Platform specific code is:
    - platform initialization
    - pcm device selection
    - pcm stream configuration
    - sound device selection
    - acdb ID selection
    - HDMI configuration

Change-Id: I9b02d60035ea632776e59c9d953909d3b851f3d7