sound control: squashed commits of faux123 sound control

Thanks @faux123

Change-Id: I35243a63d074ed5bb1ed824dd3e254e77c54baf6
sound control: (Optional) work around for WCD93xx audio issues

(Use this only for devices with audio reset issues)

Also bump version to 3.1

Signed-off-by: Paul Reioux <reioux@gmail.com>

wcd9xxx-core: add register write without mutex protection

This is assuming the calling function will take care of the mutex.

Signed-off-by: Paul Reioux <reioux@gmail.com>
sound control: (Optional) add power amp registers access control as well

Signed-off-by: Paul Reioux <reioux@gmail.com>
sound control: add register cache

bump to version 3.2

Signed-off-by: Paul Reioux <reioux@gmail.com>