binman: Update entry_test to support Python 3

The reload() function is in a different place in Python 3. Update the code
to handle this.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/entry_test.py

@@ -41,6 +41,10 @@ class TestEntry(unittest.TestCase):
         del sys.modules['importlib']
         global entry
         if entry:
+            if sys.version_info[0] >= 3:
+                import importlib
+                importlib.reload(entry)
+            else:
                 reload(entry)
         else:
             import entry