control: Add timer trigger support

When an event is configured with a "timer" trigger, the event's actions
are run after the configured type of timer expires.

Change-Id: I4a400cdae0df560ba58383916c246c10d27d3516
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/Makefile.am b/control/Makefile.am
index 74f28dc..8f0a11e 100644
--- a/control/Makefile.am
+++ b/control/Makefile.am
@@ -35,7 +35,8 @@
 	json/actions/missing_owner_target.cpp \
 	json/actions/count_state_target.cpp \
 	json/actions/net_target_increase.cpp \
-	json/actions/net_target_decrease.cpp
+	json/actions/net_target_decrease.cpp \
+	json/triggers/timer.cpp
 else
 phosphor_fan_control_SOURCES += \
 	argument.cpp \