ASoC: msm: set the master gain to 0 on DSP while configuring

- Mute media volume and play any music clip then reboot
  the phone. Play music again noise comes. This noise
  is introduced in DSP/LPASS.

- DSP suggestion is to mute master volume gain while
  configuring ASM session to avoid such noise at
  begining of asm playback.

Change-Id: I2aa2846d6e3e9a85c459534e9108e6fe7aebb962
Signed-off-by: Ramjee Singh <ramjee@codeaurora.org>