eventdev: add weight and affinity to queue attributes

eventdev: add weight and affinity to queue attributes

Extended eventdev queue QoS attributes to support weight and affinity.
If queues are of the same priority, events from the queue with highest
weight will be scheduled first. Affinity indicates the number of times,
the subsequent schedule calls from an event port will use the same event
queue. Schedule call selects another queue if current queue goes empty
or schedule count reaches affinity count.

To avoid ABI break, weight and affinity attributes are not yet added to
queue config structure and rely on PMD for managing it. New eventdev op
queue_attr_get can be used to get it from the PMD.

Signed-off-by: Shijith Thotton <sthotton@marvell.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>