USB: EHCI: add separate IAA watchdog timer

This patch (as1028) was mostly written by David Brownell; I made only
a few changes (extra log info and a small bug fix -- which might
account for why David's version had to be reverted).  It adds a new
watchdog timer to the ehci-hcd driver to be used exclusively for
detecting lost or missing IAA notifications.

Previously a shared timer had been used, which may have led to some
problems as reported by Christian Hoffmann.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index a165e0a..a249d03 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -134,7 +134,7 @@
 	}
 	ehci->command = ehci_readl(ehci, &ehci->regs->command);
 	if (ehci->reclaim)
-		ehci->reclaim_ready = 1;
+		end_unlink_async(ehci);
 	ehci_work(ehci);
 
 	/* Unlike other USB host controller types, EHCI doesn't have