pinctrl: Fix path error in documentation

Fix pinconfig include file path.

Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt

@@ -216,4 +216,4 @@ arguments are described below.
   or 0 to disable debouncing
 
 More in-depth documentation on these parameters can be found in
-<include/linux/pinctrl/pinconfig-generic.h>
+<include/linux/pinctrl/pinconf-generic.h>