asoc: volume control support for transcode loopback FE

Add stream volume control support for DSP transcode
loopback to enable mute configuration requirement.

Change-Id: I2003e40c9888245c1b12f0e7fbd364170d5008cf
Signed-off-by: Siddartha Shaik <sshaik@codeaurora.org>
Signed-off-by: Surendar Karka <skarka@codeaurora.org>