power: supply: axp20x_usb_power: Use power efficient workqueue for debounce

The debounce timeout is generally quite long and the work not performance
critical so allow the scheduler to run the work anywhere rather than in
the normal per-CPU workqueue.
Signed-off-by: Yangtao Li <frank@allwinnertech.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/axp20x_usb_power.c

@@ -92,7 +92,7 @@ static irqreturn_t axp20x_usb_power_irq(int irq, void *devid)
 
 	power_supply_changed(power->supply);
 
-	mod_delayed_work(system_wq, &power->vbus_detect, DEBOUNCE_TIME);
+	mod_delayed_work(system_power_efficient_wq, &power->vbus_detect, DEBOUNCE_TIME);
 
 	return IRQ_HANDLED;
 }
@@ -117,7 +117,7 @@ static void axp20x_usb_power_poll_vbus(struct work_struct *work)
 
 out:
 	if (axp20x_usb_vbus_needs_polling(power))
-		mod_delayed_work(system_wq, &power->vbus_detect, DEBOUNCE_TIME);
+		mod_delayed_work(system_power_efficient_wq, &power->vbus_detect, DEBOUNCE_TIME);
 }
 
 static int axp20x_get_current_max(struct axp20x_usb_power *power, int *val)
@@ -525,7 +525,7 @@ static int axp20x_usb_power_resume(struct device *dev)
 	while (i < power->num_irqs)
 		enable_irq(power->irqs[i++]);
 
-	mod_delayed_work(system_wq, &power->vbus_detect, DEBOUNCE_TIME);
+	mod_delayed_work(system_power_efficient_wq, &power->vbus_detect, DEBOUNCE_TIME);
 
 	return 0;
 }
@@ -647,7 +647,7 @@ static int axp20x_usb_power_probe(struct platform_device *pdev)
 
 	INIT_DELAYED_WORK(&power->vbus_detect, axp20x_usb_power_poll_vbus);
 	if (axp20x_usb_vbus_needs_polling(power))
-		queue_delayed_work(system_wq, &power->vbus_detect, 0);
+		queue_delayed_work(system_power_efficient_wq, &power->vbus_detect, 0);
 
 	return 0;
 }