eventdev: add implicit release disable capability

eventdev: add implicit release disable capability

This commit introduces a capability for disabling the "implicit" release
functionality for a port, which prevents the eventdev PMD from issuing
outstanding releases for previously dequeued events when dequeuing a new
batch of events.

If a PMD does not support this capability, the application will receive an
error if it attempts to setup a port with implicit releases disabled.
Otherwise, if the port is configured with implicit releases disabled, the
application must release each dequeued event by invoking
rte_event_enqueue_burst() with RTE_EVENT_OP_RELEASE or
RTE_EVENT_OP_FORWARD.

Signed-off-by: Gage Eads <gage.eads@intel.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>