net: dsa: felix: use vcap policer to set flow meter for psfp

This patch add police action to set flow meter table which is defined
in IEEE802.1Qci. Flow metering is two rates two buckets and three color
marker to policing the frames, we only enable one rate one bucket in
this patch.

Flow metering shares a same policer pool with VCAP policers, so the PSFP
policer calls ocelot_vcap_policer_add() and ocelot_vcap_policer_del() to
set flow meter police.

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