gpio: xtensa: Include the right header

This is a GPIO driver so include only <linux/gpio/driver.h>.
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-xtensa.c

@@ -30,7 +30,7 @@
 
 #include <linux/err.h>
 #include <linux/module.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/bitops.h>
 #include <linux/platform_device.h>