ASoC: msm8974: Fix audio ocmem driver issues during LPA playback

This change takes care of clearing all the ocmem pending requests
at the end of the lpa playback. If playback ends while waiting for
ocmem region, ocmem free is called to clear the request so that we
will not receive any grow requests further.

Change-Id: I0b94b5ff95341c433852283c70c09b006192a3a6
Signed-off-by: Phani Kumar Uppalapati <phanik@codeaurora.org>