monitor:SIGHUP: Create and use system object

Use a system object to handle retrieving the trust groups and fan
definitions configured. This is necessary for handling HUP signals in
the future where a reload of the JSON configuration is done.

Tested:
    No change in the loading of the trust groups configuration
    No change in the loading of the fan definitions configured

Change-Id: I5df2d54641f80778bbf09d7b1f4588a458e11c71
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/monitor/Makefile.am b/monitor/Makefile.am
index 185c2e3..6c3c435 100644
--- a/monitor/Makefile.am
+++ b/monitor/Makefile.am
@@ -9,7 +9,8 @@
 	fan.cpp \
 	main.cpp \
 	tach_sensor.cpp \
-	conditions.cpp
+	conditions.cpp \
+	system.cpp
 
 phosphor_fan_monitor_LDADD = \
 	$(SDBUSPLUS_LIBS) \