nfp: flower: add validation of for police actions which are independent of flows

Validation of police actions was added to offload drivers in
commit d97b4b10

 ("flow_offload: reject offload for all drivers with
invalid police parameters")

This patch extends that validation in the nfp driver to include
police actions which are created independently of flows.

Signed-off-by: Ziyang Chen <ziyang.chen@corigine.com>
Reviewed-by: Baowen Zheng <baowen.zheng@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>