wl1251: remove unnecessary import

No function declared in gpio.h is used here.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Kalle Valo <kvalo@adurom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/wl1251/boot.c

@@ -19,7 +19,6 @@
  *
  */
 
-#include <linux/gpio.h>
 #include <linux/slab.h>
 
 #include "reg.h"