gpio: syscon: Include the right header

This is a GPIO driver, include only <linux/gpio/driver.h>.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-syscon.c

@@ -10,7 +10,7 @@
  */
 
 #include <linux/err.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>