gpio: adp5520: Include proper header

This driver has no business including <linux/gpio.h>, it is a
driver so include <linux/gpio/driver.h>.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-adp5520.c

@@ -12,8 +12,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/adp5520.h>
-
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 
 struct adp5520_gpio {
 	struct device *master;