docs(changelog): changelog for v2.7 release

Change-Id: I573e5eb3c7fad097892292c8a967dc02d72d12e6
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
diff --git a/package-lock.json b/package-lock.json
index 4284d71..34e7dbd 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "trusted-firmware-a",
-  "version": "2.6.0",
+  "version": "2.7.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "trusted-firmware-a",
-      "version": "2.6.0",
+      "version": "2.7.0",
       "hasInstallScript": true,
       "license": "BSD-3-Clause",
       "devDependencies": {