assign the right traffic scheduler entity id instead of the hardcoding for PQs

Assign the right traffic scheduler entity id instead of the hardcoding them for PQs to 0x8000.

In "performSettingPQs"  function in omci_ani_config.go in openonu adapter, the traffic scheduler reference pointer is hardcoded to 0x8000 in case of WRR scheduling policy for the traffic queues.

As per Priority Queue (ME #277) definition in OMCI specification, the traffic scheduler pointer is to be set as per below description.

 
Traffic scheduler pointer: This attribute points to the traffic scheduler ME instance that is associated with this priority queue. This pointer is used when this priority queue is connected with a traffic scheduler. The default value is a null pointer (0). (R, W) (mandatory) (2 bytes) 

Note 5: When the QoS configuration flexibility attribute of the ONU2-G managed entity allows flexible assignment of the traffic scheduler, the OLT may configure the traffic scheduler pointer to refer to any traffic scheduler in the same slot. 

If traffic scheduler flexibility is not permitted by the QoS configuration flexibility attribute, the OLT may use the traffic scheduler pointer attribute only by pointing to another traffic scheduler ME that is associated with the same T-CONT as the priority queue itself. 

The ONU should reject an attempt to violate these conditions with a parameter error result-reason code.