net/mlx5e: Add header re-write offloading of IPv6 hop-limit

For environments where flow-based ipv6 router is offloaded.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>