USB: make autosuspend delay a module parameter

This patch (as859) makes the default USB autosuspend delay a module
parameter of usbcore.  By setting the delay value at boot time, users
will be able to prevent the system from autosuspending devices which
for some reason can't handle it.

The patch also stores the autosuspend delay as a per-device value.  A
later patch will allow the user to change the value, tailoring the
delay for each individual device.  A delay value of 0 will prevent
autosuspend.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/usb.h

@@ -389,10 +389,13 @@ struct usb_device {
 
 	int pm_usage_cnt;		/* usage counter for autosuspend */
 	u32 quirks;			/* quirks of the whole device */
+
 #ifdef CONFIG_PM
 	struct delayed_work autosuspend; /* for delayed autosuspends */
 	struct mutex pm_mutex;		/* protects PM operations */
 
+	unsigned autosuspend_delay;	/* in jiffies */
+
 	unsigned auto_pm:1;		/* autosuspend/resume in progress */
 	unsigned do_remote_wakeup:1;	/* remote wakeup should be enabled */
 #endif