mips: alchemy: gpio: Include the right header

The local GPIO driver in the MIPS Alchemy is including the legacy
<linux/gpio.h> header but what it wants is to implement a GPIO
driver so include <linux/gpio/driver.h> instead.

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: linux-gpio@vger.kernel.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/alchemy/common/gpiolib.c

@@ -31,7 +31,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <asm/mach-au1x00/gpio-au1000.h>
 #include <asm/mach-au1x00/gpio-au1300.h>