docs(changelog): changelog for lts-v2.8.23 release

Change-Id: Id8d27316bcadc6f6d0359f26b1f406cd41e0764f
Signed-off-by: Release CI <ci@trustedfirmware.org>
diff --git a/Makefile b/Makefile
index c4df7c2..57f2dad 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@
 #
 VERSION_MAJOR			:= 2
 VERSION_MINOR			:= 8
-VERSION_PATCH			:= 22
+VERSION_PATCH			:= 23
 VERSION				:= ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}
 
 # Default goal is build all images