nfp: flower: allow matching on ipv4 UDP tunnel tos and ttl

The addition of FLOW_DISSECTOR_KEY_ENC_IP to TC flower means that the ToS
and TTL of the tunnel header can now be matched on.

Extend the NFP tunnel match function to include these new fields.

Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>