drm/amd/display: constify a few dc_surface_update fields

	struct dc_plane_state *surface;

	/* isr safe update parameters.  null means no updates */

	struct dc_flip_addrs *flip_addr;

	struct dc_plane_info *plane_info;

	struct dc_scaling_info *scaling_info;

	const struct dc_flip_addrs *flip_addr;

	const struct dc_plane_info *plane_info;

	const struct dc_scaling_info *scaling_info;

	/* following updates require alloc/sleep/spin that is not isr safe,

	 * null means no updates

	 */

	struct dc_gamma *gamma;

	struct dc_transfer_func *in_transfer_func;

	const struct dc_gamma *gamma;

	const struct dc_transfer_func *in_transfer_func;

	struct dc_csc_transform *input_csc_color_matrix;

	struct fixed31_32 *coeff_reduction_factor;

	const struct dc_csc_transform *input_csc_color_matrix;

	const struct fixed31_32 *coeff_reduction_factor;

};

/*