This allows rules to be chained between VCAP instances, e.g. from IS0
Lookup 0 to IS0 Lookup 1, or from one of the IS0 Lookups to one of the IS2
Lookups.

Chaining from an IS2 Lookup to another IS2 Lookup is not supported in the
hardware.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>