pinctrl: Grammar s/used in as/used as/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/core.c

@@ -558,7 +558,7 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
 }
 
 /**
- * pinctrl_request_gpio() - request a single pin to be used in as GPIO
+ * pinctrl_request_gpio() - request a single pin to be used as GPIO
  * @gpio: the GPIO pin number from the GPIO subsystem number space
  *
  * This function should *ONLY* be used from gpiolib-based GPIO drivers,