drm/atomic: Remove deprecated accessor macros

Now that the last users have been converted, we can finally get rid of
for_each_obj_in_state, we have better macros to replace them with.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20170719143920.25685-8-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index feb9941..82a217b 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -539,10 +539,10 @@ struct drm_plane {
 	 * This is protected by @mutex. Note that nonblocking atomic commits
 	 * access the current plane state without taking locks. Either by going
 	 * through the &struct drm_atomic_state pointers, see
-	 * for_each_plane_in_state(), for_each_oldnew_plane_in_state(),
-	 * for_each_old_plane_in_state() and for_each_new_plane_in_state(). Or
-	 * through careful ordering of atomic commit operations as implemented
-	 * in the atomic helpers, see &struct drm_crtc_commit.
+	 * for_each_oldnew_plane_in_state(), for_each_old_plane_in_state() and
+	 * for_each_new_plane_in_state(). Or through careful ordering of atomic
+	 * commit operations as implemented in the atomic helpers, see
+	 * &struct drm_crtc_commit.
 	 */
 	struct drm_plane_state *state;