media: ipu3-cio2: Toggle sensor streaming in pm runtime ops

The .suspend() and .resume() runtime_pm operations for the ipu3-cio2
driver currently do not handle the sensor's stream. Setting .s_stream() on
or off for the sensor subdev means that sensors will pause and resume the
stream at the appropriate time even if their drivers don't implement those
operations.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Tested-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>