Document that IAR gmtime_s() is auto selected
diff --git a/ChangeLog b/ChangeLog
index 093a42b..1ba5f0e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,8 +7,8 @@
      whose implementation should behave as a thread safe version of gmtime().
      This allows users to configure such an implementation at compile time when
      the target system cannot be deduced automatically. At this stage Mbed TLS
-     is only able to automtically select implementations for Windows and POSIX
-     C libraries.
+     is only able to automatically select implementations for Windows, POSIX
+     C libraries and IAR.
 
 Bugfix
    * Fixes an issue with MBEDTLS_CHACHAPOLY_C which would not compile if