net: hns3: Add "qos prio map" info query function

This patch prints qos priority map information.

debugfs command:
echo dump qos pri map > cmd

Sample Command:
root@(none)# echo dump qos pri map > cmd
hns3 0000:7d:00.0: dump qos pri map
hns3 0000:7d:00.0: vlan_to_pri: 0x0
hns3 0000:7d:00.0: pri_0_to_tc: 0x0
hns3 0000:7d:00.0: pri_1_to_tc: 0x0
hns3 0000:7d:00.0: pri_2_to_tc: 0x0
hns3 0000:7d:00.0: pri_3_to_tc: 0x0
hns3 0000:7d:00.0: pri_4_to_tc: 0x0
hns3 0000:7d:00.0: pri_5_to_tc: 0x0
hns3 0000:7d:00.0: pri_6_to_tc: 0x0
hns3 0000:7d:00.0: pri_7_to_tc: 0x0
root@(none)#

Signed-off-by: liuzhongzhu <liuzhongzhu@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>