media: adv7511: Drop unused include

The adv7511 driver includes the legacy GPIO header <linux/gpio.h>
yet fails to use any symbols from it.

Drop the include.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

drivers/media/i2c/adv7511-v4l2.c

@@ -17,7 +17,6 @@
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/videodev2.h>
-#include <linux/gpio.h>
 #include <linux/workqueue.h>
 #include <linux/hdmi.h>
 #include <linux/v4l2-dv-timings.h>