Remove obsolete macros from compat-1.3.h
diff --git a/ChangeLog b/ChangeLog
index c9d5ec0..3e9bc2b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,8 @@
 = mbed TLS 2.1.x branch released xxxx-xx-xx
 
 Bugfix
+   * Remove macros from compat-1.3.h that correspond to deleted items from most
+     recent versions of the library. Found by Kyle Keen.
    * Fixed issue in mutexes to failing to initialise. #667
 
 = mbed TLS 2.1.7 branch released 2017-03-08