media: ov5647: Add set_fmt and get_fmt calls.

media: ov5647: Add set_fmt and get_fmt calls.

There's no way to query the subdevice for the supported
resolutions. Add set_fmt and get_fmt implementations. Since there's
only one format supported set_fmt does nothing and get returns single
format.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>