nfp: flower: include geneve as supported offload tunnel type

Offload of geneve decap rules is supported in NFP. Include geneve in the
check for supported types.

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