net/mlx5: support IP-in-IP tunnel

net/mlx5: support IP-in-IP tunnel

Enabled IP-in-IP tunnel type support on DV/DR flow engine.
This includes the following combination:
 - IPv4 over IPv4
 - IPv4 over IPv6
 - IPv6 over IPv4
 - IPv6 over IPv6

MLX5 NIC supports IP-in-IP tunnel via FLEX Parser so
need to make sure fw using FLEX Paser profile 0.

  mlxconfig -d <mst device> -y set FLEX_PARSER_PROFILE_ENABLE=0

The example testpmd commands would be:

- Match on IPv4 over IPv4 packets and do inner RSS:

  testpmd> flow create 0 ingress pattern eth / ipv4 proto is 0x04 /
           ipv4 / udp / end actions rss level 2 queues 0 1 2 3 end / end

- Match on IPv6 over IPv4 packets and do inner RSS:

  testpmd> flow create 0 ingress pattern eth / ipv4 proto is 0x29 /
           ipv6 / udp / end actions rss level 2 queues 0 1 2 3 end / end

Signed-off-by: Xiaoyu Min <jackmin@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>