docs(changelog): changelog for lts-v2.8.28 release

Change-Id: Ieaa8bf9b4d6c69be1cc6b5766e57b90b7f4e687d
Signed-off-by: Release CI <ci@trustedfirmware.org>
diff --git a/docs/conf.py b/docs/conf.py
index 4eb7e4d..daa83f1 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -14,8 +14,8 @@
 
 project = "Trusted Firmware-A"
 author = "Trusted Firmware-A contributors"
-version = "2.8.27"
-release = "2.8.27"
+version = "2.8.28"
+release = "2.8.28"
 
 # -- General configuration ---------------------------------------------------