[PATCH] V4L: Fixes maximum number of VBI devices

- Increases the minor number limitation for vbi devices from 223 to 255.
  This is in agreement with the minor number allocation specified in
  Documentation/devices.txt.

- Without this patch it is not possible to use more than 5 Hauppauge
  WinTV-PVR 350 cards since each of these allocate 3 vbi devices.

Signed-of-by: Sigmund Augdal Helberg <sigmund@snap.tv>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>