Remove 'description' attribute
Remove 'description' attribute

Since the QosPolicy model inherits from standard attributes[1],
the Standardattrdescription extension adds the 'description'
to the attributes map in the API layer[2].
So there is no need to keep it in Qos code.
[1]https://github.com/openstack/neutron/blob/master/neutron/db/qos/models.py#L26
[2]https://github.com/openstack/neutron/blob/master/neutron/extensions/standardattrdescription.py#L55

Change-Id: Ia1ba22d754c66f2976dcbd946ab688e3e2507cfb

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