work: enable/disable workq timer following each timer_set/clear()

We need enable/disable workq timer also after each calling to
set/clear timer, but not only CPU frequency change, so merge
them into work_set/clear_timer().

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
diff --git a/src/lib/work.c b/src/lib/work.c
index 55a6f90..7da6f68 100644
--- a/src/lib/work.c
+++ b/src/lib/work.c
@@ -75,11 +75,13 @@
 static inline void work_set_timer(struct work_queue *queue, uint32_t ticks)
 {
 	queue->ts->timer_set(&queue->ts->timer, ticks);
+	timer_enable(&queue->ts->timer);
 }
 
 static inline void work_clear_timer(struct work_queue *queue)
 {
 	queue->ts->timer_clear(&queue->ts->timer);
+	timer_disable(&queue->ts->timer);
 }
 
 static inline uint32_t work_get_timer(struct work_queue *queue)
@@ -308,10 +310,8 @@
 			queue->ticks_per_usec * PLATFORM_WORKQ_WINDOW;
 		queue_recalc_timers(queue, clk_data);
 		queue_reschedule(queue);
-		timer_enable(&queue->ts->timer);
 	} else if (message == CLOCK_NOTIFY_PRE) {
 		/* CPU frequency update pending */
-		timer_disable(&queue->ts->timer);
 	}
 
 	spin_unlock_irq(&queue->lock, flags);