lxc: Report supported huge pages

lxc: Report supported huge pages

There are two places where we report supported sizes of huge pages:

  /capabilities/host/cpu/pages
  /capabilities/host/topology/cells/cell/pages

The former aggregates sizes over all NUMA nodes while the latter
reports supported sizes only for given node. While we are
reporting per NUMA node sizes we are not reporting the aggregated
sizes. I've noticed this when wondering why doesn't allocpages
completer work.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>