Add match threshold alarm signals for threshold events

Add SEL_LOGGER_MONITOR_THRESHOLD_ALARM_EVENTS option to enable
monitoring the alarm signals on sensor threshold interfaces:
https://gerrit.openbmc-project.xyz/39899

Tested:
Change the threshold to trigger the alarm signal:
busctl set-property xyz.openbmc_project.Hwmon-487368426.Hwmon1
/xyz/openbmc_project/sensors/temperature/cputemp
xyz.openbmc_project.Sensor.Threshold.Critical CriticalHigh d 30

trigger the event log:
1 |  Pre-Init  |0000000213| Temperature cputemp
| Upper Critical going high | Asserted
| Reading 35 > Threshold 30 degrees C

Note:
It needs to work with the following PR:
https://gerrit.openbmc-project.xyz/42212

Signed-off-by: George Hung <george.hung@quantatw.com>
Change-Id: I86a7061895ba082643d1f9e0222b52b1bd732083
diff --git a/src/sel_logger.cpp b/src/sel_logger.cpp
index 99527b1..83d487a 100644
--- a/src/sel_logger.cpp
+++ b/src/sel_logger.cpp
@@ -24,6 +24,9 @@
 #include <sel_logger.hpp>
 #include <threshold_event_monitor.hpp>
 #include <watchdog_event_monitor.hpp>
+#ifdef SEL_LOGGER_MONITOR_THRESHOLD_ALARM_EVENTS
+#include <threshold_alarm_event_monitor.hpp>
+#endif
 
 #include <filesystem>
 #include <fstream>
@@ -248,6 +251,10 @@
     sdbusplus::bus::match::match watchdogEventMonitor =
         startWatchdogEventMonitor(conn);
 #endif
+
+#ifdef SEL_LOGGER_MONITOR_THRESHOLD_ALARM_EVENTS
+    startThresholdAlarmMonitor(conn);
+#endif
     io.run();
 
     return 0;