ASoC: msm: Add support for enabling voice post processing feature

Add support to allow enabling of voice post-processing features like
widevoice, slowtalk and far-end noise suppression during a voice call.

Change-Id: Id2e4d69b3e9f1e05bc8447027bd44a81448b0fc7
Signed-off-by: Helen Zeng <xiaoyunz@codeaurora.org>