EHCI: fix interrupt-driven remote wakeup

Now that port status change notifications are interrupt-driven,
ehci-hcd needs to tell usbcore when a remote-wakeup resume operation
is finished -- we can no longer rely on the core to poll and find
out.  This patch (as843) uses the root-hub status timer to force a
poll after the resume is complete.

The patch also changes the test for detecting when the TDRSMDN resume
period has expired.  It's necessary to use time_after_eq() instead of
time_after(), since the polling is triggered precisely by a timer.
The same change is made for TDRSTR reset expiration, for consistency.

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>