net/hns3: set max scheduling rate based on actual board

net/hns3: set max scheduling rate based on actual board

Currently, max scheduling rates configuration of pg, pri and port are
set to 100000Mbps, which is the maximum bandwidth of hns3 network engine
with revision_id equals 0x21. However, max scheduling rate configuration
should be set to hardware based on the actual hardware board
environment.

The max_tm_rate in struct hns3_hw, meaning the rate, is obtained from
firmware. So we should use the variable to configure the max scheduling
rate.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>