drm/amdgpu: Update latest xgmi topology info after each device is enumulated

Adjust the sequence of set/get xgmi topology, so driver can have the latest
XGMI topology info for future usage

Signed-off-by: shaoyunl <shaoyun.liu@amd.com>
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>