pinctrl: spear/plgpio: Pass irqchip when adding gpiochip

We need to convert all old gpio irqchips to pass the irqchip
setup along when adding the gpio_chip. For more info see
drivers/gpio/TODO.

For chained irqchips this is a pretty straight-forward
conversion.

Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20190913113530.5536-3-linus.walleij@linaro.org