wiki: Add codename prefix to subheader on devices page

Change-Id: I96d5a50ac30b98732fb32be52a6db5013cee14ad

Author: BadDaemon

pages/devices.html

@@ -272,7 +272,7 @@ <h2 class="h2" id="{{ vendorId }}" data-vendor="{{ vendorId }}">{{ device.vendor
     </div>
     {%- endif %}
     <a href="{{ url }}">
-      <span class="codename">{{ device.codename }}</span>
+      <span class="codename">codename: {{ device.codename }}</span>
     </a>
   </div>
 </div>