xhci: Show host status when watchdog triggers and host is assumed dead.

Additional debugging to show xHC USBSTS register when stop endpoint
command watchdog triggers and host is assumed dead.

useful to know the current status before the controller is stopped by
the xhci driver and everything is released and freed.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200312144517.1593-4-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>