util: Fix shebang for python2 scripts

Python 3 is the default Python interpreter on most modern systems.
Python 2 scripts must specify they should be run with Python 2 in their
shebang. Solves issue raised in CB:28953.

Change-Id: I9ace4afd668539c05e7ace30e255af50c7a069c2
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/29666
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

util/cavium/devicetree_convert.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 
 # devicetree_convert Tool to convert a DTB to a static C file
 # Copyright (C) 2018 Facebook Inc.

util/ipqheader/createxbl.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 #============================================================================
 #
 #/** @file createxbl.py

util/ipqheader/mbn_tools.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 #===============================================================================
 #
 # MBN TOOLS

util/lint/checkpatch_json.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 # Copyright (C) 2018 Intel Corporation.
 # written by Naresh G Solanki<naresh.solanki@intel.com> and
 #            Maulik V Vaghela <maulik.v.vaghela@intel.com>