stereo call recording support

Patch that allows for call recording in
stereo (left channel: TX; right channel:
RX). Tested on Nexus 5 (MSM8974). Likely
works on other recent MSM chipsets as
well.

Change-Id: I3f67ee5b83383f09b339f0af710b470f8a3a000c
Merge branch 'cm-11.0' of git://github.com/cyanogenmod/android_kernel_sony_msm8974 into 4.10Opt