net/mlx5e: Disallow inserting vxlan/vlan egress rules without decap/pop

Currently, rules on tunnel devices can be offloaded without decap action
when a vlan pop action exists. Similarly, the driver will offload rules
on vlan interfaces with no pop action when a decap action exists.

Disallow the faulty behavior by checking that vlan egress rules do pop or
drop and vxlan egress rules do decap, as intended.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>