configs: msmcobalt: update mixer controls for headphones

Headphones and Headphones-44.1 devices are using same mixer
controls which is resulting in no audio when both are enabled.
Update headphones mixer controls to use mix path.

Change-Id: I79c3badd20eb2a64c055d1c7c8d408c3b2d1f5f3
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>