tests: latency_measure: Restructure configurations

Restructures the latency_measure benchmark configurations. Most of them
do not need to be executed by default by CI. However, we still want to
make it easy to run the benchmark with various configurations so that
they can be easily compared against the default.

The updated documentation shows how this can be done.

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