mfd: asic3: Include the right header

This is a GPIO driver, use the appropriate header
<linux/gpio/driver.h> rather than the legacy <linux/gpio.h>
header.

Signed-off-by: Linus Walleij <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/asic3.c

···
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/irq.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/export.h>
 #include <linux/io.h>
 #include <linux/slab.h>