Crypto: Add frontend support for multipart AEAD APIs

This patch adds support in the TF-M Crypto service
frontend for AEAD multipart APIs.

Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: I81b55bc6ae1b0e1c1c015c90577518328a3286fa
diff --git a/interface/include/tfm_crypto_defs.h b/interface/include/tfm_crypto_defs.h
index 47d9724..2eaa28b 100644
--- a/interface/include/tfm_crypto_defs.h
+++ b/interface/include/tfm_crypto_defs.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2018-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  *
@@ -44,6 +44,8 @@
                                   *   multipart operation
                                   */
     size_t capacity;             /*!< Key derivation capacity */
+    size_t ad_length;            /*!< Additional Data length for multipart AEAD */
+    size_t plaintext_length;     /*!< Plaintext length for multipart AEAD */
 
     struct tfm_crypto_aead_pack_input aead_in; /*!< FixMe: Temporarily used for
                                                 *   AEAD until the API is
@@ -53,7 +55,9 @@
 
 /**
  * \brief Define a progressive numerical value for each SID which can be used
- *        when dispatching the requests to the service
+ *        when dispatching the requests to the service. Note: This has to
+ *        match exactly with the list of APIs defined in tfm_crypto_api.h by
+ *        the LIST_TFM_CRYPTO_UNIFORM_SIGNATURE_API X macro.
  */
 enum {
     TFM_CRYPTO_GET_KEY_ATTRIBUTES_SID = (0u),