MAINTAINERS: remove USB OV511 DRIVER

Removed by commit 7373ab36 ("V4L/DVB: Remove obsolete ov511
driver").

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Amerigo Wang <amwang@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>