ChangeLog: Enable builds as a CMake subproject
diff --git a/ChangeLog b/ChangeLog
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+++ b/ChangeLog
@@ -1,5 +1,11 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 2.18.1 branch released 2019-07-12
+
+Changes
+   * Enable building of Mbed TLS as a CMake subproject. Suggested and fixed by
+     Ashley Duncan in #2609.
+
 = mbed TLS 2.18.0 branch released 2019-06-11
 
 Features