top_dev->gpu is NULL for CPUs. Avoid dereferencing it if NULL.
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>