drm: Extract drm_color_mgmt.[hc]

For both the new degamm/lut/gamma atomic combo, and the old legacy
gamma tables.

Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474448370-32227-5-git-send-email-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index 2672f3b..c48ba02 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -58,6 +58,10 @@
 		     void *data, struct drm_file *file_priv);
 int drm_mode_setcrtc(struct drm_device *dev,
 		     void *data, struct drm_file *file_priv);
+
+/* drm_color_mgmt.c */
+
+/* IOCTLs */
 int drm_mode_gamma_get_ioctl(struct drm_device *dev,
 			     void *data, struct drm_file *file_priv);
 int drm_mode_gamma_set_ioctl(struct drm_device *dev,