Update version_features.c

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/library/version_features.c b/library/version_features.c
index d16ad1b..f5ea798 100644
--- a/library/version_features.c
+++ b/library/version_features.c
@@ -519,6 +519,9 @@
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
     "MBEDTLS_SSL_PROTO_TLS1_2",
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+    "MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL",
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     "MBEDTLS_SSL_PROTO_DTLS",
 #endif /* MBEDTLS_SSL_PROTO_DTLS */