[media] bt819: the ioctls in the header are internal to the kernel

Remove bt819.h from ioctl-number.txt and make a note in the header
that these ioctls are for internal use only.

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

Documentation/ioctl/ioctl-number.txt

@@ -193,7 +193,6 @@ Code  Seq#(hex)	Include File		Comments
 					<http://lrcwww.epfl.ch/>
 'b'	00-FF				conflict! bit3 vme host bridge
 					<mailto:natalia@nikhefk.nikhef.nl>
-'b'	00-0F	media/bt819.h		conflict!
 'c'	all	linux/cm4000_cs.h	conflict!
 'c'	00-7F	linux/comstats.h	conflict!
 'c'	00-7F	linux/coda.h		conflict!