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>
ASoc: msm: update the pending buffer flags in underrun

Update the pending buffer flag on a driver underrun.
This causes a drain call to be rejected if the underrun
happens immediately after an EOS buffer has been given to the DSP
following a flush

CRs-Fixed: 463332
Change-Id: I2ba224a49e5af14ca909300afc0788cb4b21eb16
Signed-off-by: Subhash Chandra Bose Naripeddy <snariped@codeaurora.org>
ASoC: msm: Support independent left-right channel volume control

The current volume sent to DSP is averaged between left and
right channels. As a result with volume level as zero on one
channel and non zero on the other channel results to playback on
both channels. Add support to send left and right volumes to DSP

Change-Id: Icc5f182d138c841607ea356ec37a7f78b4ba770d
CRs-Fixed: 449284
Signed-off-by: Subhash Chandra Bose Naripeddy <snariped@codeaurora.org>
Signed-off-by: Jay Wang <jaywang@codeaurora.org>