net/mlx5: fix IPIP multi-tunnel validation

net/mlx5: fix IPIP multi-tunnel validation

A flow rule must not include multiple tunnel layers.
An attempt to create such a rule, for example:
testpmd> flow create .../ vxlan / eth / ipv4 proto is 4 / end <actions>
results in an unclear error.

In the current implementation there is a check for
multiple IPIP tunnels, but not for combination of IPIP
and a different kind of tunnel, such as VXLAN. The fix
is to enhance the above check to use MLX5_FLOW_LAYER_TUNNEL
that consists of all the tunnel masks. The error message
will be "multiple tunnel not supported".

Fixes: 5e33bebdd8d3 ("net/mlx5: support IP-in-IP tunnel")
Cc: stable@dpdk.org
Signed-off-by: Lior Margalit <lmargalit@nvidia.com>
Acked-by: Ori Kam <orika@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>