nfp: flower: fix masks for tcp and ip flags fields

Check mask fields of tcp and ip flags when setting the corresponding mask
flag used in hardware.

Fixes: 8f256622

 ("flow_offload: add flow_rule and flow_match")
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>