Add tests todo label

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>

tests/opt-testcases/tls13-misc.sh

@@ -456,3 +456,11 @@ run_test "TLS 1.3 G->m: EarlyData: psk*: size exceeds the limit, fail." \
          -s "EncryptedExtensions: early_data(42) extension exists."         \
          -s "Received early data size exceeds limitation."                  \
          -S "Ignore application message"
+
+# TODO: Add test for max_early_data_size. For time being, we do not have a
+#       suitable client for it. GnuTLS client does not consider about it.
+#       If MbedTLS is ready, add tests.
+#       - Server configured size change before 2nd connection. First n bytes will
+#         be received and then abort.
+#       - Client only sent data size same with max_early_data_size in 1st connection
+#       - ....