Merge pull request #11638 from JuhPuur/imgtool_python3_fix

Change imgtool lib import to relative import

Author: adbridge

tools/psa/tfm/bin_utils/imgtool.py

@@ -19,9 +19,9 @@
 import os
 import re
 import argparse
-from imgtool_lib import keys
-from imgtool_lib import image
-from imgtool_lib import version
+from .imgtool_lib import keys
+from .imgtool_lib import image
+from .imgtool_lib import version
 import sys
 
 def find_load_address(args):