Tmf: Benchmark for the request scheduler

Tmf: Benchmark for the request scheduler

The benchmark has three tests. The first one is the latency (time
between the creation of the request and the beginning of its execution).
The second one is the average waiting time for a request. The last one
is the total completion time.

Change-Id: Icc8cb47111221aaefb871faab97bb49c8bdf0b03
Signed-off-by: Simon Delisle <simon.delisle@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/14520
Reviewed-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
IP-Clean: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Tested-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>