drm/amdgpu: add nbio v7.2 for vangogh (v2)

VanGogh uses nbio v7.2, and a couple of offsets are changed since nbio
v2.3 for navi series, so add new nbio v7.2 block.

v2: squash in fix for sdma and vcn instances

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>