sdbusplus: use shorter type aliases

The sdbusplus headers provide shortened aliases for many types.
Switch to using them to provide better code clarity and shorter
lines.  Possible replacements are for:
  * bus_t
  * exception_t
  * manager_t
  * match_t
  * message_t
  * object_t
  * slot_t

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I96286490697ce5d7fecc1c9c358f5f1d054137ec
diff --git a/side-switch/side_switch.hpp b/side-switch/side_switch.hpp
index ddaa922..324edaf 100644
--- a/side-switch/side_switch.hpp
+++ b/side-switch/side_switch.hpp
@@ -7,25 +7,25 @@
  *  @param[in] bus       - The Dbus bus object
  *  @return True if side switch needed, false otherwise
  */
-bool sideSwitchNeeded(sdbusplus::bus::bus& bus);
+bool sideSwitchNeeded(sdbusplus::bus_t& bus);
 
 /** @brief Power off the system
  *
  *  @param[in] bus       - The Dbus bus object
  *  @return True if chassis off success, false otherwise
  */
-bool powerOffSystem(sdbusplus::bus::bus& bus);
+bool powerOffSystem(sdbusplus::bus_t& bus);
 
 /** @brief Configure BMC to auto power on the host after reboot
  *
  *  @param[in] bus       - The Dbus bus object
  *  @return True if policy set correctly, false otherwise
  */
-bool setAutoPowerRestart(sdbusplus::bus::bus& bus);
+bool setAutoPowerRestart(sdbusplus::bus_t& bus);
 
 /** @brief Reboot the BMC
  *
  *  @param[in] bus       - The Dbus bus object
  *  @return True if reboot request had no error, false otherwise
  */
-bool rebootTheBmc(sdbusplus::bus::bus& bus);
+bool rebootTheBmc(sdbusplus::bus_t& bus);