drivers: soc: Synchronize apr callback and voice svc release

Issue is seen when apr callback is received while voice_svc_release
is in process of freeing the driver private data.
Avoid invalid access of private data pointer by putting
the callback and release functions in the same locked context.

Change-Id: I93af13cab0a3c7e653a9bc9fa7f4f86bfa0502df
Signed-off-by: smanag <smanag@codeaurora.org>