If use GART for FB translation, place both vram and gart to sysvm aperture. AGP aperture is not set up in this case because it is not used Signed-off-by: Oak Zeng <Oak.Zeng@amd.com> Reviewed-by: Christian Konig <christian.koenig@amd.com> Reviewed-by: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>