USB / PM: Drop CONFIG_PM_RUNTIME from the USB core

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM (or even dropped in some cases).

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the USB core code
and documentation.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 2dd2362..2a92b97 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -49,7 +49,7 @@
 
 static bool nousb;	/* Disable USB when built into kernel image */
 
-#ifdef	CONFIG_PM_RUNTIME
+#ifdef	CONFIG_PM
 static int usb_autosuspend_delay = 2;		/* Default delay value,
 						 * in seconds */
 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
@@ -348,11 +348,9 @@
 	.thaw =		usb_dev_thaw,
 	.poweroff =	usb_dev_poweroff,
 	.restore =	usb_dev_restore,
-#ifdef CONFIG_PM_RUNTIME
 	.runtime_suspend =	usb_runtime_suspend,
 	.runtime_resume =	usb_runtime_resume,
 	.runtime_idle =		usb_runtime_idle,
-#endif
 };
 
 #endif	/* CONFIG_PM */