[media] media: use media_gobj inside pads

PADs also need unique object IDs that won't conflict with
the entity object IDs.

The pad objects are currently created via media_entity_init()
and, once created, never change.

While this will likely change in the future in order to
support dynamic changes, for now we'll keep PADs as arrays
and initialize the media_gobj embedded structs when
registering the entity.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index 9f6f056..2d94c85 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -48,6 +48,9 @@
 	case MEDIA_GRAPH_ENTITY:
 		gobj->id = media_gobj_gen_id(type, ++mdev->entity_id);
 		break;
+	case MEDIA_GRAPH_PAD:
+		gobj->id = media_gobj_gen_id(type, ++mdev->pad_id);
+		break;
 	}
 }