nfp: flower: implement tcp flag match offload

Implement tcp flag match offloading. Current tcp flag match support include
FIN, SYN, RST, PSH and URG flags, other flags are unsupported. The PSH and
URG flags are only set in the hardware fast path when used in combination
with the SYN, RST and PSH flags.

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