PEL: Implement CreatePELWithFFDCFiles

This D-Bus method on the org.open_power.Logging.PEL interface is the
same as the already existing createWithFFDCFiles method on the
xyz.openbmc_project.Logging.Create interface, except it also returns the
IDs of the newly created OpenBMC event log and PEL.

Code was added to track the IDs of the most recently added event log and
PEL so they they can be returned by the function.

Change-Id: I3a1e0d93f97aa1953ff8b10293b47e28f79edfb1
diff --git a/log_manager.hpp b/log_manager.hpp
index be8c8b4..2303269 100644
--- a/log_manager.hpp
+++ b/log_manager.hpp
@@ -150,11 +150,26 @@
         return propChangedEntryCallback.size();
     }
 
+    /**
+     * @brief Returns the sdbusplus bus object
+     *
+     * @return sdbusplus::bus::bus&
+     */
     sdbusplus::bus::bus& getBus()
     {
         return busLog;
     }
 
+    /**
+     * @brief Returns the ID of the last created entry
+     *
+     * @return uint32_t - The ID
+     */
+    uint32_t lastEntryID() const
+    {
+        return entryId;
+    }
+
     /** @brief Creates an event log
      *
      *  This is an alternative to the _commit() API.  It doesn't use