Add ChangeLog entries for PR and
mbed TLS ChangeLog (Sorted per branch, date)
+= mbed TLS 2.7.x branch released 2018-xx-xx
+
+Bugfix
+ * Fix the name of a DHE parameter that was accidentally changed in 2.7.0.
+ Fixes #1358.
+
+Changes
+ * Fix tag lengths and value ranges in the documentation of CCM encryption.
+ Contributed by Mathieu Briand.
+
= mbed TLS 2.7.0 branch released 2018-02-03
Security
