net: mscc: ocelot: Hardware ofload for tc flower filter

Hardware offload of port filtering are now supported via tc command using
flower filter. ACL rules are used to enable the hardware offload.
The following keys are supported:

vlan_id
vlan_prio
dst_mac/src_mac for non IP frames
dst_ip/src_ip
dst_port/src_port

The following actions are supported:
trap
drop

These filters are supported only on the ingress schedulare.

Add:
tc qdisc add dev eth3 ingress
tc filter ad dev eth3 parent ffff: ip_proto ip flower \
    ip_proto tcp dst_port 80 action drop

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>