nfp: flower: remove dead code paths

Port matching is selected by default on every rule so remove check for it
and delete 'else' side of the statement. Remove nfp_flower_meta_one as now
it will not feature in the code. Rename nfp_flower_meta_two given that one
has been removed.

'Additional metadata' if statement can never be true so remove it as well.

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