drm/amdgpu: enable Doorbell support for Renoir (v2)

Add VCN range aperture to NBIO 7.0

v2: rebase (Alex)

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