psu-ng: Move entity-manager interaces added

Move the code for handling interfacesAdded from entity-manager to the
PSUManager constructor. Plans on using this for both the system
properties from SupportedConfiguration and the IBMCFFPSConnector
properties.

Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
Change-Id: I440ffdf5a3ad77f58dc521ba743e5c984659cc69
diff --git a/phosphor-power-supply/psu_manager.cpp b/phosphor-power-supply/psu_manager.cpp
index 3117e2c..b5e07c3 100644
--- a/phosphor-power-supply/psu_manager.cpp
+++ b/phosphor-power-supply/psu_manager.cpp
@@ -22,6 +22,16 @@
     // Parse out the JSON properties
     sysProperties = {0};
     getJSONProperties(configfile);
+    // Subscribe to InterfacesAdded before doing a property read, otherwise
+    // the interface could be created after the read attempt but before the
+    // match is created.
+    entityManagerIfacesAddedMatch = std::make_unique<sdbusplus::bus::match_t>(
+        bus,
+        sdbusplus::bus::match::rules::interfacesAdded() +
+            sdbusplus::bus::match::rules::sender(
+                "xyz.openbmc_project.EntityManager"),
+        std::bind(&PSUManager::supportedConfIfaceAdded, this,
+                  std::placeholders::_1));
     getSystemProperties();
 
     using namespace sdeventplus;
@@ -80,16 +90,6 @@
 
 void PSUManager::getSystemProperties()
 {
-    // Subscribe to InterfacesAdded before doing a property read, otherwise
-    // the interface could be created after the read attempt but before the
-    // match is created.
-    entityManagerIfacesAddedMatch = std::make_unique<sdbusplus::bus::match_t>(
-        bus,
-        sdbusplus::bus::match::rules::interfacesAdded() +
-            sdbusplus::bus::match::rules::sender(
-                "xyz.openbmc_project.EntityManager"),
-        std::bind(&PSUManager::supportedConfIfaceAdded, this,
-                  std::placeholders::_1));
 
     uint64_t maxCount;
     try