Use @registry.receives in neutron.services.qos.drivers.base
Use @registry.receives in neutron.services.qos.drivers.base

Switch to registry.receives decorator in neutron.services.qos.drivers.base

Change-Id: If7532e0f08824523b55f0de53a59525d519ca7f9
Partial-Bug: #1668262

huntxu/neutron,noironetworks/neutron,openstack/neutron,eayunstack/neutron,mahak/neutron,noironetworks/neutron,eayunstack/neutron,mahak/neutron,openstack/neutron,huntxu/neutron,mahak/neutron,openstack/neutron