tbf: add 64bit rates support

tbf support 64bit rates start from linux-3.13.
Add 64bit rates support in tc tools.

tc qdisc show dev eth0
qdisc tbf 1: root refcnt 2 rate 40000Mbit burst 230000b peakrate 50000Mbit minburst 87500b lat 50.0ms

This is a followup to ("htb: support 64bit rates").

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: Eric Dumazet <edumazet@google.com>