Add platform-install as a subproject

Change-Id: I898b3bdd48aef56093c9ea02e5b067d57ef5fd1a
diff --git a/build.gradle b/build.gradle
index 42c3646..65b4c94 100644
--- a/build.gradle
+++ b/build.gradle
@@ -69,6 +69,13 @@
                     'tag':          null,
                     'componentDir': './components/cord-onos-publisher'
             ],
+            'platform-install': [
+                    'type':         'gitmodule',
+                    'upstream':     '../platform-install',
+                    'branch':       'master',
+                    'tag':          null,
+                    'componentDir': './components/platform-install'
+            ],
             'nginx': [
                     'type':     'image',
                     'upstream': upstreamReg,