mwifiex: delete unneeded include

Nothing that is defined in 11ac.h is referenced in cmdevt.c.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/cmdevt.c

@@ -25,7 +25,6 @@
 #include "main.h"
 #include "wmm.h"
 #include "11n.h"
-#include "11ac.h"
 
 static void mwifiex_cancel_pending_ioctl(struct mwifiex_adapter *adapter);