monitor: Move timer ops into TachSensor

Upcoming commits will touch the TachSensor timer
outside of the Fan class, and it will be cleaner to
encapsulate the operations in TachSensor.

Change-Id: I8584c44eb5dbe6bb93191a006d20dfc37596eeb3
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/monitor/tach_sensor.hpp b/monitor/tach_sensor.hpp
index 4691d1e..60a55e3 100644
--- a/monitor/tach_sensor.hpp
+++ b/monitor/tach_sensor.hpp
@@ -101,11 +101,32 @@
         }
 
         /**
-         * Returns the timer object for this sensor
+         * @brief Says if the timer is running or not
+         *
+         * @return bool - if timer is currently running
          */
-        inline phosphor::fan::util::Timer& getTimer()
+        inline bool timerRunning()
         {
-            return _timer;
+            return _timer.running();
+        }
+
+        /**
+         * @brief Starts the timer for the amount of time
+         *        specified in the constructor
+         */
+        inline void startTimer()
+        {
+            _timer.start(
+                    getTimeout(),
+                    phosphor::fan::util::Timer::TimerType::oneshot);
+        }
+
+        /**
+         * @brief Stops the timer
+         */
+        inline void stopTimer()
+        {
+            _timer.stop();
         }
 
         /**