net/mlx5e: TC, Add support for VxLAN GBP encap/decap flows offload

Add HW offloading support for TC flows with VxLAN GBP encap/decap.

Example of encap rule:
tc filter add dev eth0 protocol ip ingress flower \
    action tunnel_key set id 42 vxlan_opts 512 \
    action mirred egress redirect dev vxlan1

Example of decap rule:
tc filter add dev vxlan1 protocol ip ingress flower \
    enc_key_id 42 enc_dst_port 4789 vxlan_opts 1024 \
    action tunnel_key unset action mirred egress redirect dev eth0

Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Gavi Teitz <gavi@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Acked-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>