sh-pfc: Replace pinctrl_add_gpio_range() with gpiochip_add_pin_range()

Adding a GPIO range to a pinctrl device logically belongs to the GPIO
driver. Switch to the right API.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>