media: i2c: ov13b10: Drop stream handling in runtime PM handlers

The sensor is guaranteed not to be streaming when the runtime PM resume
handler is called, as the resume handler is only called from the
.s_stream() operation when starting streaming. Similarly, the sensor has
been stopped when the runtime PM suspend handler is called. There is
thus no need for manual stream start/stop from the runtime PM handlers.
Drop them.

The streaming field of the driver's private structure is now unused,
drop it as well.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>