V4L/DVB (9323): v4l2-int-if: Add enum_framesizes and enum_frameintervals ioctls.

Signed-off-by: Sakari Ailus <sakari.ailus@nokia.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>