fix test_ref_configs build fail

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 598c3ef..cea8ab5 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1753,12 +1753,16 @@
             named_group <= MBEDTLS_SSL_IANA_TLS_GROUP_FFDHE8192 );
 }
 
-#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) || \
+    defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
+    defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
 int mbedtls_ssl_write_supported_groups_ext( mbedtls_ssl_context *ssl,
                                             unsigned char *buf,
                                             const unsigned char *end,
                                             size_t *out_len );
 
-#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED ||
+          MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
+          MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
 
 #endif /* ssl_misc.h */