testsuite: add a small test suite

Featuring a self-written linpack test, which spawns as
many working threads as cpus are available.

Since it's only for internal testing, there is not much
to mention about it. Its also hidden from the user by
default.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
testsuite: bump up warumUp phase

Since its single-threaded to this point, we can safely
bump this a bit up.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>