The mcp23s08 driver was moved from gpio to pinctrl. This moves it's
devicetree binding doc as well. So driver and binding doc are in sync
again.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>