docs(changelog): changelog for lts-v2.12.4 release

Change-Id: Id513d026bf0d72a8c3cb1fb77e3e6c84964d2894
Signed-off-by: Release CI <ci@trustedfirmware.org>
diff --git a/Makefile b/Makefile
index aa446c1..037330f 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@
 VERSION_MAJOR			:= 2
 VERSION_MINOR			:= 12
 # VERSION_PATCH is only used for LTS releases
-VERSION_PATCH			:= 3
+VERSION_PATCH			:= 4
 VERSION				:= ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}
 
 # Default goal is build all images