drm/amdgpu: Save PA of bad pages for old asics

for old asics that do not support mca translating, we
just save PA for them

Signed-off-by: ganglxie <ganglxie@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>