The field current_norm does not have to be set for g_parm to be a valid
ioctl. Remove that check, but add a check whether this is a video node
instead as g_parm only makes sense for those nodes.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>