net: mscc: ocelot: set vcap IS2 chain to goto PSFP chain

Some chips in the ocelot series such as VSC9959 support Per-Stream
Filtering and Policing(PSFP), which is processing after VCAP blocks.
We set this block on chain 30000 and set vcap IS2 chain to goto PSFP
chain if hardware support.

Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>