pinctrl: ocelot: update pinctrl to automatic base address

struct gpio_chip recommends passing -1 as base to gpiolib. Doing so avoids
conflicts when the chip is external and gpiochip0 already exists.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Tested-by: Clément Léger <clement.leger@bootlin.com>
Link: https://lore.kernel.org/r/20211119195928.2498441-3-colin.foster@in-advantage.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>