spapr: Remove support for NVIDIA V100 GPU with NVLink2

NVLink2 support was removed from the PPC PowerNV platform and VFIO in
Linux 5.13 with commits :

  562d1e207d32 ("powerpc/powernv: remove the nvlink support")
  b392a1989170 ("vfio/pci: remove vfio_pci_nvlink2")

This was 2.5 years ago. Do the same in QEMU with a revert of commit
ec132efa ("spapr: Support NVIDIA V100 GPU with NVLink2"). Some
adjustements are required on the NUMA part.

Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Message-ID: <20230918091717.149950-1-clg@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>