media: si470x-i2c: add missed operations in remove

The driver misses calling v4l2_ctrl_handler_free and
v4l2_device_unregister in remove like what is done in probe failure.
Add the calls to fix it.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/radio/si470x/radio-si470x-i2c.c

@@ -482,6 +482,8 @@ static int si470x_i2c_remove(struct i2c_client *client)
 	if (radio->gpio_reset)
 		gpiod_set_value(radio->gpio_reset, 0);
 
+	v4l2_ctrl_handler_free(&radio->hdl);
+	v4l2_device_unregister(&radio->v4l2_dev);
 	return 0;
 }