USB: chipidea: re-order irq handling to avoid unhandled irqs

- let role driver handle irq before ID change check; this gives the
  role driver a chance to handle disconnect;
- disable irq during switch role; no role driver to handle irq in
  the period.

Tested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>