Asoc: msm: Add G711 media type support for Voip

G711 is currently not supported in the Voip driver.
Add G711 media type to existing Voip driver.

Change-Id: I4c8ae61e3f9b3a3fd537ca6ac26c6df40c56a78a
Signed-off-by: Prashanth Reddy <pgreddy@codeaurora.org>