wl1271: depend on INET

wl1271_main.c:(.text+0x271052): undefined reference to `unregister_inetaddr_notifier'
wl1271_main.c:(.text+0x2714d7): undefined reference to `register_inetaddr_notifier'

Driver is doing some filtering based on IP addresses...

Acked-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>