post_proc: Audiosphere SA+ concurrency implementation

Audiosphere effect cannot be used along with any other SA+
effects, and needs handling for such concurrent use cases.
Add audiosphere controls to post_proc module, here both
audiosphere and SA+ events are made available providing
easy detection and handling for concurrent use cases.

Change-Id: Ifc2ac493442dda1fbe564b066fab0710a14d1759