use qos api def from neutron-lib
use qos api def from neutron-lib

The Qos extension's API definition was rehomed into neutron-lib with
commit I8ab3712850ec02278b3efb9161fc03236926b842 and neutron will
consume it with I3bb987920008d5a1d73cf4c5f37895d7f917c368

This patch removes the global attribute map update for the qos
extension in the Unit Tests. This isn't needed and is already handled in
extension loading.

Change-Id: Ibf957616cb1acacf2a61c138d354be9ccdf640b5

openstack/networking-odl,openstack/networking-odl,openstack/networking-odl