asoc: add A2DP sink support in dai-driver

Add decoder config support for split A2DP sink.

Change-Id: If71a2b2ae7f0f0500f196b0552ab185c9f37b778
Signed-off-by: Florian Pfister <fpfister@codeaurora.org>
Signed-off-by: Surendar Karka <skarka@codeaurora.org>