Attach sdevent mainloop to dbus

Switch from sd_bus process to sd_event run so that sd event
handlers are invoked.

Change-Id: If7c1f046f30cc845c6e9fcc72eb99c5bdfb36052
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/src/sdbusplus.hpp b/src/sdbusplus.hpp
index 8afb8b5..aba5a36 100644
--- a/src/sdbusplus.hpp
+++ b/src/sdbusplus.hpp
@@ -4,6 +4,8 @@
 #include <sdbusplus/message.hpp>
 #include <sdbusplus/bus/match.hpp>
 
+struct Loop;
+
 namespace phosphor
 {
 namespace dbus
@@ -101,6 +103,8 @@
                     match,
                     callback);
         }
+
+        friend Loop;
 };
 
 } // namespace monitoring