pinctrl/mediatek: fix spelling mistake in dev_err error message

Trivial change, fix spelling mistake 'invaild' -> 'invalid' in
dev_err message.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Hongzhou Yang <hongzhou.yang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
index 0350a80..23f2de0 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
@@ -702,7 +702,7 @@
 
 	ret = mtk_pctrl_is_function_valid(pctl, g->pin, function);
 	if (!ret) {
-		dev_err(pctl->dev, "invaild function %d on group %d .\n",
+		dev_err(pctl->dev, "invalid function %d on group %d .\n",
 				function, group);
 		return -EINVAL;
 	}