drm: Use DRM_ROTATE_MASK and DRM_REFLECT_MASK

Avoid magic numbers and use the introduced defines.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/omapdrm/omap_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c
index 09e363b..3054bda 100644
--- a/drivers/gpu/drm/omapdrm/omap_plane.c
+++ b/drivers/gpu/drm/omapdrm/omap_plane.c
@@ -108,7 +108,7 @@
 	win.src_x = state->src_x >> 16;
 	win.src_y = state->src_y >> 16;
 
-	switch (state->rotation & 0xf) {
+	switch (state->rotation & DRM_ROTATE_MASK) {
 	case BIT(DRM_ROTATE_90):
 	case BIT(DRM_ROTATE_270):
 		win.src_w = state->src_h >> 16;