net sched actions: skbedit add support for mod-ing skb pkt_type

Extremely useful for setting packet type to host so i dont
have to modify the dst mac address using pedit (which requires
that i know the mac address)

Example usage:
tc filter add dev eth0 parent ffff: protocol ip pref 9 u32 \
match ip src 5.5.5.5/32 \
flowid 1:5 action skbedit ptype host

This will tag all packets incoming from 5.5.5.5 with type
PACKET_HOST

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>