docs(changelog): changelog for lts-v2.8.22 release

Change-Id: I07f6a6ebf4ca334c6384a7788852aa07577d0bd9
Signed-off-by: Release CI <ci@trustedfirmware.org>
diff --git a/docs/conf.py b/docs/conf.py
index 41c5f15..6ae9d59 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -14,8 +14,8 @@
 
 project = "Trusted Firmware-A"
 author = "Trusted Firmware-A contributors"
-version = "2.8.21"
-release = "2.8.21"
+version = "2.8.22"
+release = "2.8.22"
 
 # -- General configuration ---------------------------------------------------