pinctrl: sx150x: Add a static gpio/pinctrl pin range mapping

Without such a range, gpiolib fails with -EPROBE_DEFER, pending the
addition of the range. So, without a range, gpiolib will keep
deferring indefinitely.

Cc: stable@vger.kernel.org
Fixes: 9e80f906 ("pinctrl: Add SX150X GPIO Extender Pinctrl Driver")
Fixes: e10f72bf ("gpio: gpiolib: Generalise state persistence beyond sleep")
Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>