net: hns3: refactor dump ncl config of debugfs

Currently, the debugfs command for ncl config is implemented by
"echo xxxx > cmd", and record the information in dmesg. It's
unnecessary and heavy. To improve it, create a single file
"ncl_config" for it, and query it by command "cat ncl_config",
return the result to userspace, rather than record in dmesg.

The display style is below:
$cat ncl_config
offset | data
0x0000 | 0x00000028
0x0004 | 0x00000400
0x0008 | 0x08040201
0x000c | 0x00000000
0x0010 | 0x00040004
0x0014 | 0x00040004
0x0018 | 0x00000000
0x001c | 0x00000000
0x0020 | 0x00040004

Signed-off-by: Jiaran Zhang <zhangjiaran@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>