net: microchip: sparx5: Add tc matchall filter and enable VCAP lookups

Use a tc matchall rule with a goto action to the VCAP specific chain to
enable the VCAP lookups.
If the matchall rule is removed the VCAP lookups will be disabled
again using its cookie as lookup to find the VCAP instance.

To enable the Sparx5 IS2 VCAP on eth0 you would use this command:

    tc filter add dev eth0 ingress prio 5 handle 5 matchall \
        skip_sw action goto chain 8000000

as the first lookup in IS2 has chain id 8000000

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>