Update SEL Logger add function to accept additional metadata

This change makes the selAddSystemRecord() function a template
that can take additional metadata and pass it on to
sd_journal_send().

Tested: Sent various test messages that include additional
metadata and verified that it is correctly added to the journal
entry.

Change-Id: I43b4216d01124ce81915c092d34797b714dba787
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
diff --git a/include/threshold_event_monitor.hpp b/include/threshold_event_monitor.hpp
index de3a867..0b75114 100644
--- a/include/threshold_event_monitor.hpp
+++ b/include/threshold_event_monitor.hpp
@@ -191,7 +191,7 @@
                                " Threshold=" + std::to_string(thresholdVal));
 
         selAddSystemRecord(journalMsg, std::string(msg.get_path()), eventData,
-                           assert);
+                           assert, selBMCGenID);
     };
     sdbusplus::bus::match::match thresholdEventMatcher(
         static_cast<sdbusplus::bus::bus &>(*conn),