drm: Add DRM_ROTATE_MASK and DRM_REFLECT_MASK

Makes it cleaner to separate the two from rotation variable.

Cc: Ville Syrjälä <[e-mail]>
Signed-off-by: Joonas Lahtinen <[e-mail]>
Reviewed-by: Ville Syrjälä <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>

include/drm/drm_crtc.h

···
 }
 
 /* rotation property bits */
+#define DRM_ROTATE_MASK 0x0f
 #define DRM_ROTATE_0	0
 #define DRM_ROTATE_90	1
 #define DRM_ROTATE_180	2
 #define DRM_ROTATE_270	3
+#define DRM_REFLECT_MASK (~DRM_ROTATE_MASK)
 #define DRM_REFLECT_X	4
 #define DRM_REFLECT_Y	5