ASoC: msm: qdsp6v2: set stream volume before starting it

Volume gains for a stream should be set before sending
RUN command to DSP. This will avoid any glitch in audio
which might occur because of rapid change in volume level
while setting up the appropriate volume for the stream.

CRs-Fixed: 753619
Change-Id: Ib9270929759852f671bf3677f6e4cc826997b76a
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>