hal: Add support for adaptive bitrate

Add support for adaptive bitrate with A2DP Offload.
Changes include separate sample rate for Slimbus Rx and
Tx backend, Tx feedback path setup on SLIMBUS_7_TX from
BTSoC to LPASS, AFE port configuration for A2DP encoder
and decoder.

Change-Id: I3b339e5525c9b6dab2e83f50bb4d63cd5d73850e