[media] v4l2-framework: update documentation

'parent' was renamed to 'dev_parent'. Clarify how/when this should be used.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
1 file changed