Use menuconfig objects - CONFIG_ISDN_I4L

Remove a menu statement and several dependencies from the Kconfig files in
the drivers/isdn tree as they have become unnecessary by the transformation
of CONFIG_ISDN from "menu, config" into "menuconfig".
(Modified version of a patch originally proposed by Jan Engelhardt.)

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Jan Engelhardt <jengelh@computergmbh.de>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>