pinctrl: bcm-iproc: 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: Pramod Kumar <pramodku@broadcom.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190812132554.18313-1-linus.walleij@linaro.org
Acked-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>