Staging: fix wireless drivers depends

These drivers can (erroneously) be enabled even when
CONFIG_NET=n, CONFIG_NETDEVICES=n, CONFIG_WLAN=n, etc.
Stop this.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>