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

As user can't specify queue id in cat command, driver will return info
of all queue id.

The display style is below:
$ cat tm_map
queue_id   qset_id   pri_id   tc_id
0000         0000      00       00
INDEX | TM BP QSET MAPPING:
0000  | 00000000:00000000:00000000:00000000:00000000:00000000:00000000
0256  | 00000000:00000000:00000000:00000000:00000000:00000002:00000000
0512  | 00000000:00000000:00000000:00000004:00000000:00000000:00000000
0768  | 00000000:00000008:00000000:00000000:00000000:00000000:00000000
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>