tests: latency_measure: Increase verbosity of summary lines

Feedback from the previous summary line change has been that it
had become more difficult for people to parse and understand what
is being tested/benchmarked when the description consisted of
just using a terse tag. To improve the situation a more human
oriented description has been added to follow that tag so that
not only can tools still parse on the tag, but people can use
both tag and the extra description to understand the test/benchmark.

Summary lines for each test now consist of the following:
    1. A terse tag (for tools to parse)
    2. A more human oriented description.
    3. Number of cycles.
    4. Number of nanoseconds.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>