ASoC: msm: Fix SRS key not being sent to DSP sometimes problem

SRS parameters are not updated sometimes when new adm session is
opened and DSP picks up invalid key from default values and plays
some undesired demo ring or noise. Fix this by sending the SRS
parameters everytime adm session is opened. Add a flag to check
if SRS is ever enabled and send parameters only if flag is set

Change-Id: Ib22e6ff74e4376936caa510a632a6a3c3727e034
Signed-off-by: Sriranjan Srikantam <cssrika@codeaurora.org>