Update Changelog for recent timer changes
diff --git a/ChangeLog b/ChangeLog
index 10b6820..9df31f9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -123,6 +123,10 @@
      mbedtls_ssl_conf_transport()
      mbedtls_ssl_conf_max_version()
      mbedtls_ssl_conf_min_version()
+   * DTLS no longer hard-depends on TIMING_C, but uses a callback interface
+     instead, see mbedtls_ssl_set_timer_cb(), with the Timing module providing
+     an example implementation, see mbedtls_timing_delay_context and
+     mbedtls_timing_set/get_delay().
 
 Changes
    * mbedtls_ctr_drbg_random() and mbedtls_hmac_drbg_random() are now