net: hns3: refactor dump qos pause cfg of debugfs

mainline inclusion
from mainline-master
commit 6571ec2e
category: feature
bugzilla: 173966
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6571ec2eda65d4e19244bb3e001ec64a6eef41dc



----------------------------------------------------------------------

Currently, user gets pause config by implementing debugfs command
"echo dump qos pause cfg > cmd", this command will dump info in dmesg.
It's unnecessary and heavy.

To optimize it, create a single file "qos_pause_cfg" in tm directory
and use cat command to get info. It will return info to userspace,
rather than record in dmesg.

The display style is below:
$ cat qos_pause_cfg
pause_trans_gap: 0x7f
pause_trans_time: 0xffff

Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Junxin Chen <chenjunxin1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>