pinctrl: imx: remove duplicated const

fix smatch warning:
drivers/pinctrl/pinctrl-imx.c:435:21: warning: duplicate const

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinctrl-imx.c b/drivers/pinctrl/pinctrl-imx.c
index 44e9726..63866d9 100644
--- a/drivers/pinctrl/pinctrl-imx.c
+++ b/drivers/pinctrl/pinctrl-imx.c
@@ -432,7 +432,7 @@
 {
 	unsigned int pin_func_id;
 	int ret, size;
-	const const __be32 *list;
+	const __be32 *list;
 	int i, j;
 	u32 config;