patman: Update test_util to run doc tests

At present this function does not run the doctests. Allow the caller to
pass these modules in as strings.

Update patman to use this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/patman/main.py b/tools/patman/main.py
index e5be28e..c01ae36 100755
--- a/tools/patman/main.py
+++ b/tools/patman/main.py
@@ -134,23 +134,11 @@
     import doctest
     from patman import func_test
 
-    sys.argv = [sys.argv[0]]
     result = unittest.TestResult()
-    suite = unittest.TestSuite()
-    loader = unittest.TestLoader()
-    for module in (test_checkpatch.TestPatch, func_test.TestFunctional):
-        if args.testname:
-            try:
-                suite.addTests(loader.loadTestsFromName(args.testname, module))
-            except AttributeError:
-                continue
-        else:
-            suite.addTests(loader.loadTestsFromTestCase(module))
-    suite.run(result)
-
-    for module in ['gitutil', 'settings', 'terminal']:
-        suite = doctest.DocTestSuite(module)
-        suite.run(result)
+    test_util.RunTestSuites(
+        result, False, False, False, None, None, None,
+        [test_checkpatch.TestPatch, func_test.TestFunctional,
+         'gitutil', 'settings', 'terminal'])
 
     sys.exit(test_util.ReportResult('patman', args.testname, result))