ieee1394: remove devfs support

Devfs has been disabled in the last kernel releases, so let's
remove it from ieee1394core, raw1394, video1394, dv1394.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>