gpio: rdc321x: 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-rdc321x.c

@@ -25,7 +25,7 @@
 #include <linux/spinlock.h>
 #include <linux/platform_device.h>
 #include <linux/pci.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/mfd/rdc321x.h>
 #include <linux/slab.h>