PM: Reorganize device PM initialization

Make the device power management initialization more straightforward
by moving the initialization of common (i.e. used by both runtime PM
and system suspend) fields to a separate routine.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 0113adc..7bd1fe4 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -57,20 +57,17 @@
 static int async_error;
 
 /**
- * device_pm_init - Initialize the PM-related part of a device object.
+ * device_pm_sleep_init - Initialize system suspend-related device fields.
  * @dev: Device object being initialized.
  */
-void device_pm_init(struct device *dev)
+void device_pm_sleep_init(struct device *dev)
 {
 	dev->power.is_prepared = false;
 	dev->power.is_suspended = false;
 	init_completion(&dev->power.completion);
 	complete_all(&dev->power.completion);
 	dev->power.wakeup = NULL;
-	spin_lock_init(&dev->power.lock);
-	pm_runtime_init(dev);
 	INIT_LIST_HEAD(&dev->power.entry);
-	dev->power.power_state = PMSG_INVALID;
 }
 
 /**