drm/amdgpu: update xgmi num links info post gc9.4.2

GC IP 9.4.2 and up support TA reporting of the number
of xGMI links between peers.

Tested-by: Vignesh Chander <vignesh.chander@amd.com>
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>