net/mlx5: support GTP

net/mlx5: support GTP

This patch adds to MLX5 PMD support of matching on GTP item,
fields msg_type and teid, according to RFC [1].
GTP item validation and translation functions are added and called.
GTP tunnel type is added to supported tunnels.

[1] http://mails.dpdk.org/archives/dev/2019-December/152799.html

Signed-off-by: Dekel Peled <dekelp@mellanox.com>
Acked-by: Ori Kam <orika@mellanox.com>