i2c / ACPI: Assign IRQ for devices that have GpioInt automatically

Following what DT already does. If the device does not have ACPI Interrupt
resource but instead it has one or more GpioInt resources listed below it,
we take the first GpioInt resource, convert it to suitable Linux IRQ number
and pass it to the driver instead.

This makes drivers simpler because the don't need to care about GPIOs at
all if only thing they need is interrupt.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>