pylibfdt: use python3 shebang

The default Python version for pylibfdt is already Python 3 but if
called without specifiying an interpreter, the setup.py script gets
called with Python 2.

It's of course still possible to call setup.py with python2 directly.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Message-Id: <20190907152530.25102-1-luca@z3ntu.xyz>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

pylibfdt/setup.py

@@ -1,6 +1,9 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
 
+# While Python 3 is the default, it's also possible to invoke
+# this setup.py script with Python 2.
+
 """
 setup.py file for SWIG libfdt
 Copyright (C) 2017 Google, Inc.