Import setup from setuptools

setuptools 60 uses its own bundled version of distutils, by default. It
injects this into sys.modules, at import time. So we need to make sure
that it is imported, before anything else imports distutils, to ensure
everything is using the same distutils version.

This change in setuptools is to prepare for Python 3.12, which will drop
distutils.

In this case, the best way to deal with the problem is to just use
setuptools' setup().

Fixes: https://bugs.debian.org/1022482

setup.py

@@ -15,8 +15,7 @@
 
 import os
 import sys
-from distutils.core import setup
-from setuptools import find_packages
+from setuptools import find_packages, setup
 
 DESCRIPTION = "The tools to build, test, and work with Mbed OS"
 OWNER_NAMES = "Jimmy Brisson, Brian Daniels"