drm: Make the .mode_fixup() operations mode argument a const pointer

The passed mode must not be modified by the operation, make it const.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/cirrus/cirrus_mode.c b/drivers/gpu/drm/cirrus/cirrus_mode.c
index 100f630..a44d31a 100644
--- a/drivers/gpu/drm/cirrus/cirrus_mode.c
+++ b/drivers/gpu/drm/cirrus/cirrus_mode.c
@@ -97,7 +97,7 @@
  * to just pass that straight through, so this does nothing
  */
 static bool cirrus_crtc_mode_fixup(struct drm_crtc *crtc,
-				   struct drm_display_mode *mode,
+				   const struct drm_display_mode *mode,
 				   struct drm_display_mode *adjusted_mode)
 {
 	return true;
@@ -429,8 +429,8 @@
 
 
 static bool cirrus_encoder_mode_fixup(struct drm_encoder *encoder,
-				  struct drm_display_mode *mode,
-				  struct drm_display_mode *adjusted_mode)
+				      const struct drm_display_mode *mode,
+				      struct drm_display_mode *adjusted_mode)
 {
 	return true;
 }