ASoc: msm: Add volume support for compressed and pcm driver.

Add support for controlling pcm and compressed audio
volume from DSP for Multimedia3 and Multimedia8 driver nodes
respectively.

Change-Id: I770a614c835474565479e70afe89f404f301ec41
Signed-off-by: Ashish Jain <ashishj@codeaurora.org>

Conflicts:
	sound/soc/msm/mpq8064.c