psa_util: change guard for mbedtls_psa_get_random() to CRYPTO_CLIENT

This commit also:
- updates changelog
- add a stub function to be used in component_test_psa_crypto_client()
  test

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/ChangeLog.d/8825.txt b/ChangeLog.d/8825.txt
index b7a2487..f892f80 100644
--- a/ChangeLog.d/8825.txt
+++ b/ChangeLog.d/8825.txt
@@ -1,6 +1,6 @@
 Features
    * mbedtls_psa_get_random() is always available as soon as
-     MBEDTLS_PSA_CRYPTO_C is enabled at build time and psa_crypto_init() is
+     MBEDTLS_PSA_CRYPTO_CLIENT is enabled at build time and psa_crypto_init() is
      called at runtime. This together with MBEDTLS_PSA_RANDOM_STATE can be
      used as random number generator function(f_rng) and context (p_rng) in
      legacy functions.
diff --git a/include/mbedtls/psa_util.h b/include/mbedtls/psa_util.h
index f79178d..c78cc23 100644
--- a/include/mbedtls/psa_util.h
+++ b/include/mbedtls/psa_util.h
@@ -21,7 +21,7 @@
  * otherwise error codes would be unknown in test_suite_psa_crypto_util.data.*/
 #include <mbedtls/asn1write.h>
 
-#if defined(MBEDTLS_PSA_CRYPTO_C)
+#if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
 
 /** The random generator function for the PSA subsystem.
  *
@@ -139,7 +139,7 @@
 {
     return (mbedtls_md_type_t) (psa_alg & PSA_ALG_HASH_MASK);
 }
-#endif /* MBEDTLS_PSA_CRYPTO_C */
+#endif /* MBEDTLS_PSA_CRYPTO_CLIENT */
 
 #if defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA)
 
diff --git a/library/psa_util.c b/library/psa_util.c
index 7384bf1..4ccc5b0 100644
--- a/library/psa_util.c
+++ b/library/psa_util.c
@@ -18,7 +18,7 @@
 
 #include "psa_util_internal.h"
 
-#if defined(MBEDTLS_PSA_CRYPTO_C)
+#if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
 
 #include <psa/crypto.h>
 
@@ -363,7 +363,7 @@
     }
 }
 
-#endif /* MBEDTLS_PSA_CRYPTO_C */
+#endif /* MBEDTLS_PSA_CRYPTO_CLIENT */
 
 #if defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA)
 
diff --git a/library/psa_util_internal.h b/library/psa_util_internal.h
index 3e62d5f..70a08a0 100644
--- a/library/psa_util_internal.h
+++ b/library/psa_util_internal.h
@@ -16,7 +16,7 @@
 
 #include "psa/crypto.h"
 
-#if defined(MBEDTLS_PSA_CRYPTO_C)
+#if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
 
 /*************************************************************************
  * FFDH
@@ -96,5 +96,5 @@
                           sizeof(error_list)/sizeof(error_list[0]),   \
                           fallback_f)
 
-#endif /* MBEDTLS_PSA_CRYPTO_C */
+#endif /* MBEDTLS_PSA_CRYPTO_CLIENT */
 #endif /* MBEDTLS_PSA_UTIL_INTERNAL_H */
diff --git a/tests/src/psa_crypto_stubs.c b/tests/src/psa_crypto_stubs.c
new file mode 100644
index 0000000..be01121
--- /dev/null
+++ b/tests/src/psa_crypto_stubs.c
@@ -0,0 +1,25 @@
+/** \file psa_crypto_stubs.c
+ *
+ * \brief Stub functions when MBEDTLS_PSA_CRYPTO_CLIENT is enabled but
+ *        MBEDTLS_PSA_CRYPTO_C is disabled.
+ */
+
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
+#include <psa/crypto.h>
+
+#if defined(MBEDTLS_PSA_CRYPTO_CLIENT) && !defined(MBEDTLS_PSA_CRYPTO_C)
+
+psa_status_t psa_generate_random(uint8_t *output,
+                                 size_t output_size)
+{
+    (void) output;
+    (void) output_size;
+
+    return PSA_ERROR_COMMUNICATION_FAILURE;
+}
+
+#endif /* MBEDTLS_PSA_CRYPTO_CLIENT !MBEDTLS_PSA_CRYPTO_C */