This adds support for decoding VCAP rules with a minimum number of
attributes: address, rule size and keyset.

This allows for a quick inspection of a VCAP instance to determine if the
rule are present and in the correct order.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>