tools/thermal: Add util library

The next changes will provide a couple of tools using some common
functions provided by this library.

It provides basic wrappers for:

 - mainloop
 - logging
 - timestamp

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20220420160933.347088-3-daniel.lezcano@linaro.org