ASoC: sdm845: Add mixer controls for AUX PCM bit format

AUX PCM ports supports multiple bit formats for Rx and Tx paths.
Add new mixer controls for supporting bit format for Rx and
Tx paths of all 4 AUX PCM ports in SDM845 target. The bit format
for the AUX PCM ports will be used to setup Backend DAI configuration
through fixup function.

Change-Id: I70372c8ba3443972b74dc3f05a2289c4e27bb11c
Signed-off-by: Xiaoyu Ye <benyxy@codeaurora.org>