drm: Simplify drm_for_each_legacy_plane arguments

No need to pass the planelist when everyone just uses
dev->mode_config.plane_list anyway.

I want to add a pile more of iterators with unified (obj, dev)
arguments. This is just prep.
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

drivers/gpu/drm/i915/intel_pm.c

@@ -2356,7 +2356,7 @@ static void ilk_compute_wm_parameters(struct drm_crtc *crtc,
 	p->pri.horiz_pixels = intel_crtc->config->pipe_src_w;
 	p->cur.horiz_pixels = intel_crtc->base.cursor->state->crtc_w;
 
-	drm_for_each_legacy_plane(plane, &dev->mode_config.plane_list) {
+	drm_for_each_legacy_plane(plane, dev) {
 		struct intel_plane *intel_plane = to_intel_plane(plane);
 
 		if (intel_plane->pipe == pipe) {

drivers/gpu/drm/shmobile/shmob_drm_crtc.c

@@ -248,7 +248,7 @@ static void shmob_drm_crtc_start(struct shmob_drm_crtc *scrtc)
 	lcdc_write(sdev, LDDDSR, value);
 
 	/* Setup planes. */
-	drm_for_each_legacy_plane(plane, &dev->mode_config.plane_list) {
+	drm_for_each_legacy_plane(plane, dev) {
 		if (plane->crtc == crtc)
 			shmob_drm_plane_setup(plane);
 	}

include/drm/drm_crtc.h

@@ -1579,8 +1579,8 @@ static inline struct drm_property *drm_property_find(struct drm_device *dev,
 }
 
 /* Plane list iterator for legacy (overlay only) planes. */
-#define drm_for_each_legacy_plane(plane, planelist) \
-	list_for_each_entry(plane, planelist, head) \
+#define drm_for_each_legacy_plane(plane, dev) \
+	list_for_each_entry(plane, &(dev)->mode_config.plane_list, head) \
 		if (plane->type == DRM_PLANE_TYPE_OVERLAY)
 
 #endif /* __DRM_CRTC_H__ */