Add missing ifdefs

Make sure that the error translating functions
are only defined when they're used.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/constant_time.c b/library/constant_time.c
index fa0d898..9b2a477 100644
--- a/library/constant_time.c
+++ b/library/constant_time.c
@@ -46,7 +46,9 @@
 #endif
 
 #include <string.h>
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC)
+#include "psa/crypto.h"
 /* Define a local translating function to save code size by not using too many
  * arguments in each translating place. */
 static int local_err_translation(psa_status_t status)