IWLWIFI should be a tristate so that if IWLCORE and/or IWL3945 are m
and none of them is y kbuild doesn't create an empty
drivers/net/wireless/built-in.o
This patch also removes the pointless "default n".
Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>