ASoc: msm: Synchronize access to compressed stream

Synchronize hw_ptr, appl_ptr access between the compressed
driver event handler and the ALSA core framework.

Signed-off-by: Haynes Mathew George <hgeorge@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>