ASoC: msm: Add incall recording support

Add two backend DAIs, and add two mixer controls to route
capture stream to the new backend DAIs. Start/stop record
commands will be sent to CVD when recording is started or
stopped after voice call is established.

Change-Id: I3a3742e43655c56267267fb3ff7dbb7c53928128
Signed-off-by: Mohan Kumar Gubbihalli Lachma Naik <mgubbi@codeaurora.org>