scripts: add version check for pyelftools

Versions before 0.24 have string handling issues in Python 3.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

scripts/gen_gdt.py

@@ -8,9 +8,15 @@ import argparse
 import sys
 import struct
 import os
+import elftools
+from distutils.version import LooseVersion
 from elftools.elf.elffile import ELFFile
 from elftools.elf.sections import SymbolTableSection
 
+if LooseVersion(elftools.__version__) < LooseVersion('0.24'):
+    sys.stderr.write("pyelftools is out of date, need version 0.24 or later\n")
+    sys.exit(1)
+
 def debug(text):
     if not args.verbose:
         return