docs(changelog): changelog for lts-v2.8.6 release

Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: I7904bb919fc78ac9ff8b4b67d187f8b09afc1a68
diff --git a/Makefile b/Makefile
index 98c4d77..43ff467 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@
 #
 VERSION_MAJOR			:= 2
 VERSION_MINOR			:= 8
-VERSION_PATCH			:= 4
+VERSION_PATCH			:= 6
 VERSION				:= ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}
 
 # Default goal is build all images