[media] v4l2-subdev.h: fix sparse error with v4l2_subdev_notify

The notify function is a void function, yet the v4l2_subdev_notify
define uses it in a ? : construction, which causes sparse warnings.

Replace the define by a static inline function and move it to
v4l2-device.h, which is where it belongs since it needs to know the
v4l2_device struct. This wasn't a problem when it was a define, but
as a static inline function this no longer compiles in v4l2-subdev.h.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index c9b1593..ffb69da 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -120,6 +120,14 @@
 int __must_check
 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
 
+/* Send a notification to v4l2_device. */
+static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
+				      unsigned int notification, void *arg)
+{
+	if (sd && sd->v4l2_dev && sd->v4l2_dev->notify)
+		sd->v4l2_dev->notify(sd, notification, arg);
+}
+
 /* Iterate over all subdevs. */
 #define v4l2_device_for_each_subdev(sd, v4l2_dev)			\
 	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)