vfio/type1: account iommu allocations

iommu allocations should be accounted in order to allow admins to
monitor and limit the amount of iommu memory.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231130200900.2320829-1-pasha.tatashin@soleen.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>