drm/nouveau/vfn/tu102-: prepare for GSP-RM

- add R535 implementation of VFN, minus interrupt table

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230918202149.4343-23-skeggsb@gmail.com