We don't need to extend them to 64bits any more, so avoid the extra overhead.

v2: update commit message.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChunming Zhou <david1.zhou@amd.com>