pinctrl: sunrisepoint: Provide Interrupt Status register offset

Since some of the GPIO controllers use different Interrupt Status offset,
it make sense to provide it explicitly in the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>