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: I9cedddf4dc9b224ecbc2f68e6b00c0ab1885a826
diff --git a/bmc_epoch.hpp b/bmc_epoch.hpp
index b47a39b..d8abe2f 100644
--- a/bmc_epoch.hpp
+++ b/bmc_epoch.hpp
@@ -20,7 +20,7 @@
 {
   public:
     friend class TestBmcEpoch;
-    BmcEpoch(sdbusplus::bus::bus& bus, const char* objPath);
+    BmcEpoch(sdbusplus::bus_t& bus, const char* objPath);
     ~BmcEpoch();
 
     /**