Split A2DP sink: BT FM Slimbus changes

A new dai is defined in the slimbus driver
to support A2dp sink in split mechanism.

Change-Id: Ibd80f6fbfacb995fb1f1e27d8772fed2fc1fd4c5
Signed-off-by: Satish Kodishala <skodisha@codeaurora.org>
Signed-off-by: Lakshmi Pola <ppriyank@codeaurora.org>