ASoC: msm: Fix for improper volume ramp up in tunnel playback

A disturbance is heard when resuming the playback after
switching from headset to speaker and back to headset with the
music paused for more than 3 sec. This is due to, data getting
rendered with the speaker volume where it had to played with headset
volume. Fix is to set the '0' as the initial volume.

Change-Id: Ie4726a7898620fb912279270e24fa15a45a437f9
CRs-fixed: 453704
Signed-off-by: Amal Paul <amal@codeaurora.org>