Support matching on ICMP type and code.

Example usage:

tc qdisc add dev eth0 ingress

tc filter add dev eth0 protocol ip parent ffff: flower \
	indev eth0 ip_proto icmp type 8 code 0 action drop

tc filter add dev eth0 protocol ipv6 parent ffff: flower \
	indev eth0 ip_proto icmpv6 type 128 code 0 action drop
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>