drivers: mfd: fix audio mute issue after ADSP SSR

Native audio playback is muted after adsp subsystem restart,
because codec device_reset() API is called even before device_down()
API finishes execution. This causes audio to mute, as codec is not
in proper reset state. Add new lock to synchronize codec subsystem
restart APIs.

Change-Id: I2366f8b04fc6cb7d874661b948c3e9af10470107
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>