Add tiers to client-management

windows/client-management/mobile-device-enrollment.md

@@ -1,7 +1,7 @@
 ---
 title: Mobile device enrollment
 description: Learn how  mobile device enrollment verifies that only authenticated and authorized devices can be managed by their enterprise.
-ms.reviewer: 
+ms.reviewer:
 manager: aaroncz
 ms.author: vinpa
 ms.topic: article
@@ -9,7 +9,9 @@ ms.prod: windows-client
 ms.technology: itpro-manage
 author: vinaypamnani-msft
 ms.date: 08/11/2017
-ms.collection: highpri
+ms.collection:
+  - highpri
+  - tier2
 ---
 
 # Mobile device enrollment