ASoC: wcd9xxx: fix class H controller driver to handle concurrency

Fix class H controller driver's finite state machine to handle concurrent
playback.  This makes audio playback quality to be better with less power
consumption.

CRs-fixed: 506099
Change-Id: I621fa5a4df9964fda6c51c70e50ece2e783cafb6
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>