network: tc: htb: not all qdisc options is supported

Currently we can't setup: mtu, burst, cburst and r2q.

If htb class is 100Mbit (or more) and r2q in default value, in dmesg you will get:

```shell
[Tue Mar 24 17:11:07 2020] HTB: quantum of class 10001 is big. Consider r2q change.
```