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/gma500/mdfld_dsi_dpi.h b/drivers/gpu/drm/gma500/mdfld_dsi_dpi.h
index 6f76247..2b40663 100644
--- a/drivers/gpu/drm/gma500/mdfld_dsi_dpi.h
+++ b/drivers/gpu/drm/gma500/mdfld_dsi_dpi.h
@@ -65,7 +65,7 @@
 /* MDFLD DPI helper functions */
 extern void mdfld_dsi_dpi_dpms(struct drm_encoder *encoder, int mode);
 extern bool mdfld_dsi_dpi_mode_fixup(struct drm_encoder *encoder,
-				struct drm_display_mode *mode,
+				const struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode);
 extern void mdfld_dsi_dpi_prepare(struct drm_encoder *encoder);
 extern void mdfld_dsi_dpi_commit(struct drm_encoder *encoder);