nfp: flower: replace CFI with vlan present

Replace vlan CFI bit with a vlan present bit that indicates the
presence of a vlan tag. Previously the driver incorrectly assumed
that an vlan id of 0 is not matchable, therefore we indicate vlan
presence with a vlan present bit.

Fixes: 5571e8c9

 ("nfp: extend flower matching capabilities")
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>