pinctrl: freescale: make mxs_regs const

Make these const as they are only stored in the const field of a
mxs_pinctrl_soc_data structure.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/freescale/pinctrl-imx23.c

@@ -257,7 +257,7 @@ static const struct pinctrl_pin_desc imx23_pins[] = {
 	MXS_PINCTRL_PIN(EMI_CLKN),
 };
 
-static struct mxs_regs imx23_regs = {
+static const struct mxs_regs imx23_regs = {
 	.muxsel = 0x100,
 	.drive = 0x200,
 	.pull = 0x400,

drivers/pinctrl/freescale/pinctrl-imx28.c

@@ -373,7 +373,7 @@ static const struct pinctrl_pin_desc imx28_pins[] = {
 	MXS_PINCTRL_PIN(EMI_CKE),
 };
 
-static struct mxs_regs imx28_regs = {
+static const struct mxs_regs imx28_regs = {
 	.muxsel = 0x100,
 	.drive = 0x300,
 	.pull = 0x600,