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

A disturbance heard when switching from one song to the other,
or when the song is paused for greater than 3 seconds and then
resumed. This is due to the previous value of the track volume
being used in the lpa driver. Fix by setting 0 as the initial
volume

Change-Id: I95e17533f6e2b66f242486dc89477f667af7c4c1
Signed-off-by: Subhash Chandra Bose Naripeddy <snariped@codeaurora.org>