app/testeventdev: add perf queue test

app/testeventdev: add perf queue test

This is a performance test case that aims at testing the following:
1. Measure the number of events can be processed in a second.
2. Measure the latency to forward an event.

The perf queue test configures the eventdev with Q queues and P ports,
where Q is nb_producers * nb_stages and P is nb_workers + nb_producers.

The user can choose the number of workers, the number of producers and
number of stages through the --wlcores , --plcores and the --stlist
application command line arguments respectively.

The producer(s) injects the events to eventdev based the
first stage sched type list requested by the user through --stlist
the command line argument.

Based on the number of stages to process(selected through --stlist),
the application forwards the event to next upstream queue and
terminates when it reaches the last stage in the pipeline.
On event termination, application increments the number events
processed and print periodically in one second to get the
number of events processed in one second.

When --fwd_latency command line option selected, the application
inserts the timestamp in the event on the first stage and then
on termination, it updates the number of cycles to forward
a packet. The application uses this value to compute the average
latency to a forward packet.

Example command to run perf queue test:
sudo build/app/dpdk-test-eventdev --vdev=event_sw0 -- --test=perf_queue\
--slcore=1 --plcores=2 --wlcore=3 --stlist=p --nb_pkts=1000000000

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>