drm/amdgpu: Avoid rma causes GPU duplicate reset

Try to ensure poison creation handle is completed in time
to set device rma value.

Signed-off-by: Ce Sun <cesun102@amd.com>
Signed-off-by: Stanley.Yang <Stanley.Yang@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>