Update mbedtls_pk_wrap_as_opaque() documentation for ECDH derivation usage
@@ -923,7 +923,8 @@ int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n );
* change or be removed at any time without notice.
*
* \note Only ECDSA keys are supported so far. Signing with the
- * specified hash is the only allowed use of that key.
+ * specified hash & ECDH key agreement derivation operation
+ * are the only allowed use of that key.
*
* \param pk Input: the EC key to import to a PSA key.
* Output: a PK context wrapping that PSA key.
