Use sub-device active state. Employ control handler lock to
synchronize access to the active state and s_stream.
Signed-off-by: Mikhail Rudenko <mike.rudenko@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>