ACPI: Use struct dev_pm_ops for power management in the button driver

Make the ACPI button driver define its PM callbacks through
a struct dev_pm_ops object rather than by using legacy PM hooks
in struct acpi_device_ops.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

drivers/acpi/button.c

@@ -76,19 +76,21 @@ MODULE_DEVICE_TABLE(acpi, button_device_ids);
 
 static int acpi_button_add(struct acpi_device *device);
 static int acpi_button_remove(struct acpi_device *device, int type);
-static int acpi_button_resume(struct acpi_device *device);
 static void acpi_button_notify(struct acpi_device *device, u32 event);
 
+static int acpi_button_resume(struct device *dev);
+static SIMPLE_DEV_PM_OPS(acpi_button_pm, NULL, acpi_button_resume);
+
 static struct acpi_driver acpi_button_driver = {
 	.name = "button",
 	.class = ACPI_BUTTON_CLASS,
 	.ids = button_device_ids,
 	.ops = {
 		.add = acpi_button_add,
-		.resume = acpi_button_resume,
 		.remove = acpi_button_remove,
 		.notify = acpi_button_notify,
 	},
+	.drv.pm = &acpi_button_pm,
 };
 
 struct acpi_button {
@@ -308,8 +310,9 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
 	}
 }
 
-static int acpi_button_resume(struct acpi_device *device)
+static int acpi_button_resume(struct device *dev)
 {
+	struct acpi_device *device = to_acpi_device(dev);
 	struct acpi_button *button = acpi_driver_data(device);
 
 	if (button->type == ACPI_BUTTON_TYPE_LID)