docs(changelog): changelog for lts-v2.10.13 release

Change-Id: I00abacb9426e515cd7f1ded4ab483c5d39ce83d5
Signed-off-by: Release CI <ci@trustedfirmware.org>
diff --git a/Makefile b/Makefile
index 1c9d4d9..9c4a838 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@
 VERSION_MAJOR			:= 2
 VERSION_MINOR			:= 10
 # VERSION_PATCH is only used for LTS releases
-VERSION_PATCH			:= 12
+VERSION_PATCH			:= 13
 VERSION				:= ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}
 
 # Default goal is build all images