drm/amd/display: add a license to cursor_reg_cache.h

It's MIT.

Fixes: b73353f7 ("drm/amd/display: Use the same cursor info across features")
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/inc/hw/cursor_reg_cache.h

+/* SPDX-License-Identifier: MIT */
 /* Copyright © 2022 Advanced Micro Devices, Inc. All rights reserved. */
 
 #ifndef __DAL_CURSOR_CACHE_H__