Platform: nuvoton m2354: update for tf-m v1.6

Change-Id: I937f4a8148fe2c161be584c9a462c1886ff50b9f

Author: wschang0

platform/ext/platform_introduction.rst

@@ -49,6 +49,8 @@ Platforms introduction
           <https://developer.arm.com/products/system-design/development-boards/cortex-m-prototyping-systems/mps2>`_
         - `M2351.
           <https://www.nuvoton.com/products/iot-solution/iot-platform/numaker-pfm-m2351/>`_
+        - `M2354.
+          <https://www.nuvoton.com/board/numaker-m2354/>`_
 
     - Dual Core Cortex-M system: