docs: add troido adk link

Change-Id: Ib7cb1dd821dc17ffc8acd02843218e6d21e15295

Author: scottamain

docs/html/guide/topics/usb/adk.jd

@@ -97,6 +97,9 @@ page.title=Android Open Accessory Development Kit
       <li><a href="http://www.sparkfun.com/products/10748">
         SparkFun</a></li>
 
+      <li><a href="http://troido.de/de/shoplsmallgbuy-android-stufflsmallg">
+        Troido</a></li>
+
       </ol>
     </div>
   </div>