virtio: pm: use CONFIG_PM_SLEEP instead of CONFIG_PM

The freeze and restore functions defined in virtio drivers are used
for suspend and hibernate, so CONFIG_PM_SLEEP is more appropriate than
CONFIG_PM. This patch replace all CONFIG_PM with CONFIG_PM_SLEEP for
virtio drivers that implement freeze and restore callbacks.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/virtio/virtio_balloon.c

@@ -513,7 +513,7 @@ static void virtballoon_remove(struct virtio_device *vdev)
 	kfree(vb);
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 static int virtballoon_freeze(struct virtio_device *vdev)
 {
 	struct virtio_balloon *vb = vdev->priv;
@@ -556,7 +556,7 @@ static struct virtio_driver virtio_balloon_driver = {
 	.probe =	virtballoon_probe,
 	.remove =	virtballoon_remove,
 	.config_changed = virtballoon_changed,
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 	.freeze	=	virtballoon_freeze,
 	.restore =	virtballoon_restore,
 #endif