Generate memory poisoning in wrappers

Generate memory poisoning code in test wrappers for:
* psa_sign_hash_start()
* psa_sign_hash_complete()
* psa_verify_hash_start()

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/tests/scripts/generate_psa_wrappers.py b/tests/scripts/generate_psa_wrappers.py
index a2d8787..4e8ee6c 100755
--- a/tests/scripts/generate_psa_wrappers.py
+++ b/tests/scripts/generate_psa_wrappers.py
@@ -143,6 +143,10 @@
         """Whether the specified buffer argument to a PSA function should be copied.
         """
         #pylint: disable=too-many-return-statements
+        if function_name in ('psa_sign_hash_start',
+                             'psa_sign_hash_complete',
+                             'psa_verify_hash_start'):
+            return True
         if function_name.startswith('psa_pake'):
             return True
         if function_name.startswith('psa_aead'):