nfp: abm: save RED's parameters

Use the new driver Qdisc structure to keep track of parameters
of RED Qdiscs.  This way as the Qdisc moves around in the hierarchy
we will be able to configure the HW appropriately.

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>