media: ipu3-cio2: Drop comment blocks for subdev op handlers

The V4L2 subdev .get_fmt() and .set_fmt() pad operation handlers have a
short documentation block that merely duplicates information from the
V4L2 subdev API documentation. They offer no value, and are prone to
bit-rotting as shown by the @cfg parameter documentation being outdated.
Drop them.

Signed-off-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>