drm/amdgpu: use physical_node_id to calculate aper_base

Similar as xgmi connected gpu nodes, physical_node_id
* segment_size should be used to calculate the offset
of aper_base.

The asic type check is redundant. once physical_node_id
and segment_size are initialized, it should be count
on.

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>