[media] cx88: set dev_parent to the correct parent PCI bus

The cx88 driver has one v4l2_device, but the video nodes are owned by two
different PCI busses. So the dev_parent pointer should be set to the correct
parent bus, otherwise sysfs won't show the correct device hierarchy.
This broke starting in 3.6 after a driver change, so this patch resurrects
the correct behavior.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/pci/cx88/cx88-core.c

@@ -1034,7 +1034,14 @@ struct video_device *cx88_vdev_init(struct cx88_core *core,
 	if (NULL == vfd)
 		return NULL;
 	*vfd = *template_;
+	/*
+	 * The dev pointer of v4l2_device is NULL, instead we set the
+	 * video_device dev_parent pointer to the correct PCI bus device.
+	 * This driver is a rare example where there is one v4l2_device,
+	 * but the video nodes have different parent (PCI) devices.
+	 */
 	vfd->v4l2_dev = &core->v4l2_dev;
+	vfd->dev_parent = &pci->dev;
 	vfd->release = video_device_release;
 	snprintf(vfd->name, sizeof(vfd->name), "%s %s (%s)",
 		 core->name, type, core->board.name);