nfp: flower: compile match for IPv6 tunnels

IPv6 tunnel matches are now supported by firmware. Modify the NFP driver
to compile these match rules. IPv6 matches are handled similar to IPv4
tunnels with the difference the address length. The type of tunnel is
indicated by the same bitmap that is used in IPv4 with an extra bit
signifying that the IPv6 variation should be used.

Only compile IPv6 tunnel matches when the fw features symbol indicated
that they are compatible with the currently loaded fw.

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