Hook up PSAMacroCollector to PSAMacroEnumerator

Make it possible to enumerate the key types, algorithms, etc.
collected by PSAMacroCollector.

This commit ensures that all fields of PSAMacroEnumerator are filled
by code inspection. Testing of the result may reveal more work to be
done in later commits.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/generate_psa_constants.py b/scripts/generate_psa_constants.py
index d0d1f3f..ff07ecd 100755
--- a/scripts/generate_psa_constants.py
+++ b/scripts/generate_psa_constants.py
@@ -304,7 +304,7 @@
 
     def _make_key_usage_code(self):
         return '\n'.join([self._make_bit_test('usage', bit)
-                          for bit in sorted(self.key_usages)])
+                          for bit in sorted(self.key_usage_flags)])
 
     def write_file(self, output_file):
         """Generate the pretty-printer function code from the gathered