tSapEgressQueueExpedite specifies the priority that this queue should
be assigned by the hardware level schedulers.
The value 'auto-expedited' implies that this attribute should be
dynamically updated by looking at the forwarding classes mapping
into this queue. In such a case the queue is treated as
'non-expedited' if there is even a single non-expedited forwarding
class using this queue.
This attribute is associated with the queue at the time of creation
and cannot be modified thereafter.