SH: shmobile: Consolidate time keeping and irq enable

Enable core cpuidle timekeeping and irq enabling and remove that
handling from this code.
Signed-off-by: Robert Lee <rob.lee@linaro.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/sh/kernel/cpu/shmobile/cpuidle.c

@@ -29,7 +29,6 @@ static int cpuidle_sleep_enter(struct cpuidle_device *dev,
 				int index)
 {
 	unsigned long allowed_mode = SUSP_SH_SLEEP;
-	ktime_t before, after;
 	int requested_state = index;
 	int allowed_state;
 	int k;
@@ -47,11 +46,7 @@ static int cpuidle_sleep_enter(struct cpuidle_device *dev,
 	 */
 	k = min_t(int, allowed_state, requested_state);
 
-	before = ktime_get();
 	sh_mobile_call_standby(cpuidle_mode[k]);
-	after = ktime_get();
-
-	dev->last_residency = (int)ktime_to_ns(ktime_sub(after, before)) >> 10;
 
 	return k;
 }
@@ -60,6 +55,7 @@ static struct cpuidle_device cpuidle_dev;
 static struct cpuidle_driver cpuidle_driver = {
 	.name			= "sh_idle",
 	.owner			= THIS_MODULE,
+	.en_core_tk_irqen	= 1,
 };
 
 void sh_mobile_setup_cpuidle(void)