nfp: abm: pass band parameter to functions

In preparation for per-band RED offload pass band parameter to
functions.  For now it will always be 0.

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