drm/mediatek: plane: Remove plane zpos/index

It is not actually useful to a mtk plane to know its zpos/index, so just
remove this field.

This let's completely remove struct mtk_drm_plane in a follow up patch.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1470279597-60453-3-git-send-email-bibby.hsieh@mediatek.com

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -559,7 +559,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 				(zpos == 1) ? DRM_PLANE_TYPE_CURSOR :
 						DRM_PLANE_TYPE_OVERLAY;
 		ret = mtk_plane_init(drm_dev, &mtk_crtc->planes[zpos],
-				     BIT(pipe), type, zpos);
+				     BIT(pipe), type);
 		if (ret)
 			goto unprepare;
 	}

drivers/gpu/drm/mediatek/mtk_drm_plane.c

@@ -189,8 +189,7 @@ static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {
 };
 
 int mtk_plane_init(struct drm_device *dev, struct mtk_drm_plane *mtk_plane,
-		   unsigned long possible_crtcs, enum drm_plane_type type,
-		   unsigned int zpos)
+		   unsigned long possible_crtcs, enum drm_plane_type type)
 {
 	int err;
 
@@ -203,7 +202,6 @@ int mtk_plane_init(struct drm_device *dev, struct mtk_drm_plane *mtk_plane,
 	}
 
 	drm_plane_helper_add(&mtk_plane->base, &mtk_plane_helper_funcs);
-	mtk_plane->idx = zpos;
 
 	return 0;
 }

drivers/gpu/drm/mediatek/mtk_drm_plane.h

@@ -20,7 +20,6 @@
 
 struct mtk_drm_plane {
 	struct drm_plane		base;
-	unsigned int			idx;
 };
 
 struct mtk_plane_pending_state {
@@ -53,7 +52,6 @@ to_mtk_plane_state(struct drm_plane_state *state)
 }
 
 int mtk_plane_init(struct drm_device *dev, struct mtk_drm_plane *mtk_plane,
-		   unsigned long possible_crtcs, enum drm_plane_type type,
-		   unsigned int zpos);
+		   unsigned long possible_crtcs, enum drm_plane_type type);
 
 #endif