PSA: fix wording for implementation defined types

There were remnants of the PSA specification wording in the
documentation that can be confusing in Mbed TLS.

We need to make it clear what the consequences of being implementation
defined are in Mbed TLS.

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 632006d..074cc93 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -938,8 +938,8 @@
  *   \endcode
  *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation. */
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice. */
 typedef struct psa_hash_operation_s psa_hash_operation_t;
 
 /** \def PSA_HASH_OPERATION_INIT
@@ -1307,9 +1307,10 @@
  *   operation = psa_mac_operation_init();
  *   \endcode
  *
+ *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation. */
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice. */
 typedef struct psa_mac_operation_s psa_mac_operation_t;
 
 /** \def PSA_MAC_OPERATION_INIT
@@ -1732,8 +1733,8 @@
  *   \endcode
  *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation. */
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice. */
 typedef struct psa_cipher_operation_s psa_cipher_operation_t;
 
 /** \def PSA_CIPHER_OPERATION_INIT
@@ -2261,8 +2262,8 @@
  *   \endcode
  *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation. */
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice. */
 typedef struct psa_aead_operation_s psa_aead_operation_t;
 
 /** \def PSA_AEAD_OPERATION_INIT
@@ -3260,8 +3261,8 @@
  *   \endcode
  *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation.
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice.
  */
 typedef struct psa_key_derivation_s psa_key_derivation_operation_t;
 
@@ -4134,8 +4135,8 @@
 /** The type of the data strucure for PAKE cipher suites.
  *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation.
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice.
  */
 typedef struct psa_pake_cipher_suite_s psa_pake_cipher_suite_t;
 
@@ -4198,8 +4199,8 @@
  *   \endcode
  *
  * This is an implementation-defined \c struct. Applications should not
- * make any assumptions about the content of this structure except
- * as directed by the documentation of a specific implementation. */
+ * make any assumptions about the content of this structure.
+ * Implementation details can change in future versions without notice. */
 typedef struct psa_pake_operation_s psa_pake_operation_t;
 
 /** \def PSA_PAKE_OPERATION_INIT