rt-tests: Add hwlatdetect package

rt-tests: Add hwlatdetect package

Split out rt-tests into rt-tests and hwlatdetect packages as the latter
requires python and we want to be able to install the core rt-tests on
minimal systems without python.

This also addresses QA warnings about the hwlatdetect files not being
packaged.

Add an RRECOMMENDS on the hwlat kernel module package for the new
hwlatdetect package as the python test requires the kernel module to
function properly (but we probably don't want to kill a build if the
exact kernel module package is not available).

(From OE-Core rev: 0ea5e5a805e038ecfeb6b87ca05c021c5f72c5e9)

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>