hal: Avoid hardcode of channel mask

Mono channel wave clips are playing at faster
rate in deep buffer usecase because channel mask
value is hardcoded to STEREO value.
As there is no check for deep buffer
usecase to override default value,
assign input channel mask value as default value.

Change-Id: Ia74b48984d6055bb0b322c65fe421e8af5d1eddf
1 file changed