Finalize ChangeLog

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/ChangeLog b/ChangeLog
index f8cd778..2c90676 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,6 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
-= mbed TLS x.x.x branch released xxxx-xx-xx
+= mbed TLS 2.25.0 branch released 2020-12-11
 
 API changes
    * The numerical values of the PSA Crypto API macros have been updated to