drm: RIP mode_config->rotation_property

Now that all drivers have been converted over to the per-plane rotation
property, we can just nuke the global rotation property.

v2: Rebase due to BIT(),__builtin_ffs() & co.
    Deal with superfluous code shuffling

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1477077768-4274-4-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index f817063..1b5a32d 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -705,8 +705,7 @@
 		state->src_w = val;
 	} else if (property == config->prop_src_h) {
 		state->src_h = val;
-	} else if (property == config->rotation_property ||
-		   property == plane->rotation_property) {
+	} else if (property == plane->rotation_property) {
 		if (!is_power_of_2(val & DRM_ROTATE_MASK))
 			return -EINVAL;
 		state->rotation = val;
@@ -766,8 +765,7 @@
 		*val = state->src_w;
 	} else if (property == config->prop_src_h) {
 		*val = state->src_h;
-	} else if (property == config->rotation_property ||
-		   property == plane->rotation_property) {
+	} else if (property == plane->rotation_property) {
 		*val = state->rotation;
 	} else if (property == plane->zpos_property) {
 		*val = state->zpos;