Switch sd_event loops to sdeventplus

This change is mostly focused around plumbing the sdeventplus::Event
object everywhere and using the member functions provided for the event.
No migration to the timer utility is performed yet.

Change-Id: I912ab82bc081239d3b7c3cf7c5caca6742ef9c87
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/monitor/Makefile.am b/monitor/Makefile.am
index cb9b8a4..e8d9bbd 100644
--- a/monitor/Makefile.am
+++ b/monitor/Makefile.am
@@ -19,12 +19,14 @@
 phosphor_fan_monitor_LDADD = \
 	$(top_builddir)/libfan.la \
 	$(SDBUSPLUS_LIBS) \
+	$(SDEVENTPLUS_LIBS) \
 	$(PHOSPHOR_LOGGING_LIBS) \
 	${PHOSPHOR_DBUS_INTERFACES_LIBS} \
 	-lstdc++fs
 
 phosphor_fan_monitor_CXXFLAGS = \
 	$(SDBUSPLUS_CFLAGS) \
+	$(SDEVENTPLUS_CFLAGS) \
 	$(PHOSPHOR_LOGGING_CFLAGS) \
 	${PHOSPHOR_DBUS_INTERFACES_CFLAGS} \
 	-flto