control: Switch to using static instance of bus

Update main to use the static reference of the bus from
util::SDBusPlus.getBus() and have each object that needs the bus call
that same util::SDBusPlus.getBus() function to retrieve the same static
reference.

Change-Id: Icd5a0e61819bf1bec8b46daae05443fdcc542b05
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/json/event.hpp b/control/json/event.hpp
index 9b108fe..2608014 100644
--- a/control/json/event.hpp
+++ b/control/json/event.hpp
@@ -74,12 +74,11 @@
      * Parses and populates a configuration event from JSON object data
      *
      * @param[in] jsonObj - JSON object
-     * @param[in] bus - sdbusplus bus object
      * @param[in] mgr - Manager of this event
      * @param[in] groups - Available groups that can be used
      * @param[in] zones - Reference to the configured zones
      */
-    Event(const json& jsonObj, sdbusplus::bus::bus& bus, Manager* mgr,
+    Event(const json& jsonObj, Manager* mgr,
           std::map<configKey, std::unique_ptr<Group>>& groups,
           std::map<configKey, std::unique_ptr<Zone>>& zones);