Fix Association interface

Mapper changed to only allow the new interface, update
to it.

Tested: Mapper showed all associations

Change-Id: I8b252c70e9f27b083a438393c731fbeb3e2ca0e5
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/PSUSensor.cpp b/src/PSUSensor.cpp
index 015a367..a7156a7 100644
--- a/src/PSUSensor.cpp
+++ b/src/PSUSensor.cpp
@@ -59,8 +59,7 @@
     }
     setInitialProperties(conn);
 
-    association =
-        objectServer.add_interface(dbusPath, "org.openbmc.Associations");
+    association = objectServer.add_interface(dbusPath, association::interface);
 
     createInventoryAssoc(conn, association, configurationPath);
     setupRead();