docs/pinctrl: fix pinctrl_select_state examples

The function requires two arguments.

Signed-off-by: Siarhei Volkau <lis8215@gmail.com>
Link: https://lore.kernel.org/r/20221101205159.1468069-2-lis8215@gmail.com


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