docs(changelog): changelog for lts-v2.8.21 release

Change-Id: I5defda97abcdbe7ac0258fadea40dd51d09cb846
Signed-off-by: Release CI <ci@trustedfirmware.org>
diff --git a/Makefile b/Makefile
index 0e4bc8b..78be314 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@
 #
 VERSION_MAJOR			:= 2
 VERSION_MINOR			:= 8
-VERSION_PATCH			:= 20
+VERSION_PATCH			:= 21
 VERSION				:= ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}
 
 # Default goal is build all images
diff --git a/docs/change-log.md b/docs/change-log.md
index 5541764..1a7871a 100644
--- a/docs/change-log.md
+++ b/docs/change-log.md
@@ -3,6 +3,52 @@
 This document contains a summary of the new features, changes, fixes and known
 issues in each release of Trusted Firmware-A.
 
+## [lts-2.8.21](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/refs/tags/lts-v2.8.20..refs/tags/lts-v2.8.21) (2024-09-20)
+
+### Resolved Issues
+
+- **Services**
+
+  - **SPM**
+
+    - **SPM MM**
+
+      - carve out NS buffer TZC400 region ([d1f63ab](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/d1f63aba22b1bfd9765ef4b17f396829b3d40888))
+
+- **Libraries**
+
+  - **CPU Support**
+
+    - workaround for Cortex-A720 erratum 2792132 ([9db99a3](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/9db99a3e47f29cec66cc1e2afee5175cf3af320a))
+    - workaround for Cortex-A720 erratum 2844092 ([dedcbb7](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/dedcbb78ee7709c7261869717f9152b485c09b89))
+    - workaround for Cortex-X4 erratum 2816013 ([7512450](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/75124503fedeaf0d5ad2f915caa15f345a608bba))
+
+### New Features
+
+- **Platforms**
+
+  - **Arm**
+
+    - **FVP**
+
+      - add cpu power control ([4220b83](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/4220b8313841c14459d86864b4bdc7f4b61a096d))
+
+- **Libraries**
+
+  - **CPU Support**
+
+    - workaround for Cortex-A520(2938996) and Cortex-X4(2726228) ([a0a574d](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/a0a574d700abfe066da72d70052c84c89ac66616))
+
+### Documentation
+
+- **Platforms**
+
+  - **Arm**
+
+    - **FVP**
+
+      - update FVP versions used ([d9daf13](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/d9daf130c27171d7de3d0b6c788d242721aade37))
+
 ## [lts-2.8.20](https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/refs/tags/lts-v2.8.19..refs/tags/lts-v2.8.20) (2024-06-28)
 
 ### Miscellaneous
diff --git a/docs/conf.py b/docs/conf.py
index 3837ed5..41c5f15 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -14,8 +14,8 @@
 
 project = "Trusted Firmware-A"
 author = "Trusted Firmware-A contributors"
-version = "2.8.20"
-release = "2.8.20"
+version = "2.8.21"
+release = "2.8.21"
 
 # -- General configuration ---------------------------------------------------
 
diff --git a/package-lock.json b/package-lock.json
index a211c12..1b9dea8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "trusted-firmware-a",
-  "version": "2.8.20",
+  "version": "2.8.21",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "trusted-firmware-a",
-      "version": "2.8.20",
+      "version": "2.8.21",
       "hasInstallScript": true,
       "license": "BSD-3-Clause",
       "devDependencies": {
diff --git a/package.json b/package.json
index 1da7eb9..ed41850 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "trusted-firmware-a",
-  "version": "2.8.20",
+  "version": "2.8.21",
   "license": "BSD-3-Clause",
   "private": true,
   "scripts": {
diff --git a/pyproject.toml b/pyproject.toml
index f154d76..3d69d91 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "trusted-firmware-a"
-version = "2.8.20"
+version = "2.8.21"
 description = "Trusted Firmware-A (TF-A) Python dependencies."
 authors = ["Arm Ltd."]
 license = "BSD-3-Clause"
diff --git a/readme.rst b/readme.rst
index cdb34a3..f522141 100644
--- a/readme.rst
+++ b/readme.rst
@@ -53,3 +53,4 @@
 
 
 
+
diff --git a/tools/conventional-changelog-tf-a/package.json b/tools/conventional-changelog-tf-a/package.json
index b7f5386..be02711 100644
--- a/tools/conventional-changelog-tf-a/package.json
+++ b/tools/conventional-changelog-tf-a/package.json
@@ -1,6 +1,6 @@
 {
   "name": "conventional-changelog-tf-a",
-  "version": "2.8.20",
+  "version": "2.8.21",
   "license": "BSD-3-Clause",
   "private": true,
   "main": "index.js",