ASoC: msm: extend audio stream app type cfg mixer with bit width

With above extended mixer commands, bit width can be achieved
from fe_dai_app_type_cfg by FE, BE and session type.

Change-Id: I09596ac27b4327a94139b9da0e04befac45c3f30
Signed-off-by: Hongtao Peng <hongtaop@codeaurora.org>