USB: Move runtime PM callbacks to usb_device_pm_ops

USB defines usb_device_type pointing to usb_device_pm_ops that
provides system-wide PM callbacks only and usb_bus_type pointing to
usb_bus_pm_ops that provides runtime PM callbacks only.  However,
the USB runtime PM callbacks may be defined in usb_device_pm_ops
which makes it possible to drop usb_bus_pm_ops and will allow us
to consolidate the handling of subsystems by the PM core code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 079cb57..d9d4b16 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -315,6 +315,11 @@
 	.thaw =		usb_dev_thaw,
 	.poweroff =	usb_dev_poweroff,
 	.restore =	usb_dev_restore,
+#ifdef CONFIG_USB_SUSPEND
+	.runtime_suspend =	usb_runtime_suspend,
+	.runtime_resume =	usb_runtime_resume,
+	.runtime_idle =		usb_runtime_idle,
+#endif
 };
 
 #endif	/* CONFIG_PM */