Add help functions to query and reset RAS UTCL2 poison status.

v2: implement it on amdgpu side and kfd only calls it.
Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>