s390/zcrypt: Convert to PM ops

Switch the zcrypt bus from legacy suspend/resume callbacks to dev_pm_ops.
The conversion is straight forward with the help of SIMPLE_DEV_PM_OPS().
The new dev_pm_ops based version is functionally equivalent to the legacy
callbacks version.

This will allow to eventually remove support for legacy suspend/resume
callbacks from the kernel altogether.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/crypto/ap_bus.c

@@ -1273,7 +1273,7 @@ static int ap_uevent (struct device *dev, struct kobj_uevent_env *env)
 	return retval;
 }
 
-static int ap_dev_suspend(struct device *dev, pm_message_t state)
+static int ap_dev_suspend(struct device *dev)
 {
 	struct ap_device *ap_dev = to_ap_dev(dev);
 
@@ -1287,11 +1287,6 @@ static int ap_dev_suspend(struct device *dev, pm_message_t state)
 	return 0;
 }
 
-static int ap_dev_resume(struct device *dev)
-{
-	return 0;
-}
-
 static void ap_bus_suspend(void)
 {
 	ap_suspend_flag = 1;
@@ -1356,12 +1351,13 @@ static struct notifier_block ap_power_notifier = {
 	.notifier_call = ap_power_event,
 };
 
+static SIMPLE_DEV_PM_OPS(ap_bus_pm_ops, ap_dev_suspend, NULL);
+
 static struct bus_type ap_bus_type = {
 	.name = "ap",
 	.match = &ap_bus_match,
 	.uevent = &ap_uevent,
-	.suspend = ap_dev_suspend,
-	.resume = ap_dev_resume,
+	.pm = &ap_bus_pm_ops,
 };
 
 void ap_device_init_reply(struct ap_device *ap_dev,