[WEXT] net_device: Don't include wext bits if not required.

This patch makes the wext bits in struct net_device depend on
CONFIG_WIRELESS_EXT.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -352,12 +352,13 @@ struct net_device
 	struct net_device_stats* (*get_stats)(struct net_device *dev);
 	struct net_device_stats	stats;
 
+#ifdef CONFIG_WIRELESS_EXT
 	/* List of functions to handle Wireless Extensions (instead of ioctl).
 	 * See <net/iw_handler.h> for details. Jean II */
 	const struct iw_handler_def *	wireless_handlers;
 	/* Instance data managed by the core of Wireless Extensions. */
 	struct iw_public_data *	wireless_data;
-
+#endif
 	const struct ethtool_ops *ethtool_ops;
 
 	/*