ASoC: rt5677: Include gpio driver header

The header file is needed because struct gpio_chip is
placed in struct rt5677_priv.
Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt5677.h

@@ -13,6 +13,7 @@
 #define __RT5677_H__
 
 #include <sound/rt5677.h>
+#include <linux/gpio/driver.h>
 
 /* Info */
 #define RT5677_RESET				0x00