Read constant names from crypto_extra.h as well as crypto_values.h

test_psa_constant_names.py was originally written before the split of
crypto.h into crypto_values.h and more, so it now needs to read
crypto_values.h as well.

In both generate_psa_constants.py and test_psa_constant_names.py, read
crypto_extra.h as well. We don't currently define any value there, but
it's plausible that we will one day.
diff --git a/tests/scripts/test_psa_constant_names.py b/tests/scripts/test_psa_constant_names.py
index 0201755..d8f0005 100755
--- a/tests/scripts/test_psa_constant_names.py
+++ b/tests/scripts/test_psa_constant_names.py
@@ -294,7 +294,8 @@
                         action='store_false', dest='keep_c',
                         help='Don\'t keep the intermediate C file (default)')
     options = parser.parse_args()
-    headers = [os.path.join(options.include[0], 'psa/crypto.h')]
+    headers = [os.path.join(options.include[0], 'psa', h)
+               for h in ['crypto.h', 'crypto_extra.h', 'crypto_values.h']]
     test_suites = ['tests/suites/test_suite_psa_crypto_metadata.data']
     inputs = gather_inputs(headers, test_suites)
     count, errors = run_tests(options, inputs)