[MLBEDSW-3687] Update setup.py with new OS support

Updated setup.py with Microsoft Windows support.

Change-Id: I8cb042002c5530601e7ce2b3c99d40342886c3a9
Signed-off-by: Fredrik Svedberg <Fredrik.Svedberg@arm.com>
diff --git a/setup.py b/setup.py
index bb2e8a0..c62944a 100644
--- a/setup.py
+++ b/setup.py
@@ -64,6 +64,7 @@
         "Intended Audience :: Developers",
         "License :: OSI Approved :: Apache Software License",
         "Operating System :: POSIX :: Linux",
+        "Operating System :: Microsoft :: Windows",
         "Programming Language :: C",
         "Programming Language :: C++ :: C++11",
         "Programming Language :: Python :: 3",