net/mlx5e: Re-eanble client vlan TX acceleration

This reverts commit cd58c714 "net/mlx5e: Disable client vlan TX acceleration".

Bring back client vlan insertion offload, the original
performance issue was found and fixed in the next patch.

Signed-off-by: Achiad Shochat <achiad@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>