Move parse_binary_string function to psa_crypto_helpers
Add test code for pbkdf2 in psa_exercise_key

Signed-off-by: Kusumit Ghoderao <Kusumit.Ghoderao@silabs.com>
diff --git a/tests/include/test/psa_exercise_key.h b/tests/include/test/psa_exercise_key.h
index b5e3d35..46f4d08 100644
--- a/tests/include/test/psa_exercise_key.h
+++ b/tests/include/test/psa_exercise_key.h
@@ -119,6 +119,7 @@
  * The inputs \p input1 and \p input2 are, in order:
  * - HKDF: salt, info.
  * - TKS 1.2 PRF, TLS 1.2 PSK-to-MS: seed, label.
+ * - PBKDF2: input cost, salt.
  *
  * \param operation         The operation object to use.
  *                          It must be in the initialized state.