ehci: Check individual port status registers on resume

If a device plug/unplug is detected on an ATI SB700 USB controller in D3,
it appears to set the port status register but not the controller status
register. As a result we'll fail to detect the plug event. Check the port
status register on resume as well in order to catch this case.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable <stable@kernel.org> [after .39-rc1 is out]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>