drm: rcar-du: Remove zpos field from rcar_du_vsp_plane_state structure

Since commit 2fc4d838 ("drm: rcar: use generic code for managing
zpos plane property") the rcar-du driver stores the plane zpos in the
drm_plane_state structure. The commit however forgot to remove the zpos
field from the rcar_du_vsp_plane_state structure. Remove it.

Fixes: 2fc4d838 ("drm: rcar: use generic code for managing zpos plane property")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/rcar-du/rcar_du_vsp.h

@@ -45,7 +45,6 @@ static inline struct rcar_du_vsp_plane *to_rcar_vsp_plane(struct drm_plane *p)
  * @format: information about the pixel format used by the plane
  * @sg_tables: scatter-gather tables for the frame buffer memory
  * @alpha: value of the plane alpha property
- * @zpos: value of the plane zpos property
  */
 struct rcar_du_vsp_plane_state {
 	struct drm_plane_state state;
@@ -54,7 +53,6 @@ struct rcar_du_vsp_plane_state {
 	struct sg_table sg_tables[3];
 
 	unsigned int alpha;
-	unsigned int zpos;
 };
 
 static inline struct rcar_du_vsp_plane_state *