mwifiex: add wext include

In trying to remove the wext includes from mac80211
and cfg80211 I found that mwifiex currently uses
them. This is wrong, it shouldn't, but to not break
it completely include wext there.

Please remove this and fix all the resulting bugs.

Cc: Bing Zhao <[e-mail]>
Signed-off-by: Johannes Berg <[e-mail]>
Acked-by: Bing Zhao <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/net/wireless/mwifiex/ioctl.h

···
 #ifndef _MWIFIEX_IOCTL_H_
 #define _MWIFIEX_IOCTL_H_
 
+#include <linux/wireless.h>
 #include <net/mac80211.h>
 
 enum {