[media] media: Move media_device link_notify operation to an ops structure

This will allow adding new operations without increasing the
media_device structure size for drivers that don't implement any media
device operation.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/exynos4-is/media-dev.c

@@ -1190,6 +1190,10 @@ static int fimc_md_link_notify(struct media_link *link, unsigned int flags,
 	return ret ? -EPIPE : 0;
 }
 
+static const struct media_device_ops fimc_md_ops = {
+	.link_notify = fimc_md_link_notify,
+};
+
 static ssize_t fimc_md_sysfs_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
@@ -1416,7 +1420,7 @@ static int fimc_md_probe(struct platform_device *pdev)
 
 	strlcpy(fmd->media_dev.model, "SAMSUNG S5P FIMC",
 		sizeof(fmd->media_dev.model));
-	fmd->media_dev.link_notify = fimc_md_link_notify;
+	fmd->media_dev.ops = &fimc_md_ops;
 	fmd->media_dev.dev = dev;
 
 	v4l2_dev = &fmd->v4l2_dev;