drm/amdgpu: Retire query_utcl2_poison_status callback

Driver switches to interrupt source id to identify
utcl2 poison event. polling interface is not needed.

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