doc: Fix a broken link in the readme.rst file

Change-Id: I53a4649b17614f711957424ddffed1dcccfc7880
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/readme.rst b/readme.rst
index cb8f800..e0be1da 100644
--- a/readme.rst
+++ b/readme.rst
@@ -255,7 +255,7 @@
 
 Arm welcomes any feedback on TF-A. If you think you have found a security
 vulnerability, please report this using the process defined in the TF-A
-`Security Centre`_. For all other feedback, please use the
+`Security Center`_. For all other feedback, please use the
 `GitHub issue tracker`_.
 
 Arm licensees may contact Arm directly via their partner managers.