[PATCH] yenta: fix build if YENTA && !CARDBUS

(struct pcmcia_socket).tune_bridge only exists if CONFIG_CARDBUS is set
but building yenta_socket without CardBus is valid.

Signed-off-by: David Vrabel <dvrabel@arcom.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>