tools: Fall back to importlib_resources on Python 3.6

importlib.resources became part of 3.7 only. Allow using distros with
3.6 and the importlib_resources backport.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

tools/binman/control.py

@@ -7,7 +7,11 @@
 
 from collections import OrderedDict
 import glob
-import importlib.resources
+try:
+    import importlib.resources
+except ImportError:
+    # for Python 3.6
+    import importlib_resources
 import os
 import pkg_resources
 import re

tools/buildman/control.py

@@ -3,7 +3,11 @@
 #
 
 import multiprocessing
-import importlib.resources
+try:
+    import importlib.resources
+except ImportError:
+    # for Python 3.6
+    import importlib_resources
 import os
 import shutil
 import subprocess

tools/patman/__main__.py

@@ -7,7 +7,11 @@
 """See README for more information"""
 
 from argparse import ArgumentParser
-import importlib.resources
+try:
+    import importlib.resources
+except ImportError:
+    # for Python 3.6
+    import importlib_resources
 import os
 import re
 import sys