pinctrl: sh-pfc: sh: Constify pins and cfg_regs arrays

The arrays are never modified, declare them as const.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/sh-pfc/pfc-sh7723.c b/drivers/pinctrl/sh-pfc/pfc-sh7723.c
index 1cecc91..4eb7eae 100644
--- a/drivers/pinctrl/sh-pfc/pfc-sh7723.c
+++ b/drivers/pinctrl/sh-pfc/pfc-sh7723.c
@@ -917,7 +917,7 @@
 	PINMUX_DATA(SIUBISLD_MARK, PSD1_PSD0_FN2, PTZ0_FN),
 };
 
-static struct sh_pfc_pin pinmux_pins[] = {
+static const struct sh_pfc_pin pinmux_pins[] = {
 	/* PTA */
 	PINMUX_GPIO(PTA7),
 	PINMUX_GPIO(PTA6),