nfp: flower: add qos offload framework

Introduce matchall filter offload infrastructure that is needed to
offload qos features like policing. Subsequent patches will make
use of police-filters for ingress rate limiting.

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