gpio: Constify platform_device_id

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mxc.c

@@ -131,7 +131,7 @@ static struct mxc_gpio_hwdata *mxc_gpio_hwdata;
 #define GPIO_INT_FALL_EDGE	(mxc_gpio_hwdata->fall_edge)
 #define GPIO_INT_BOTH_EDGES	0x4
 
-static struct platform_device_id mxc_gpio_devtype[] = {
+static const struct platform_device_id mxc_gpio_devtype[] = {
 	{
 		.name = "imx1-gpio",
 		.driver_data = IMX1_GPIO,

drivers/gpio/gpio-mxs.c

@@ -239,7 +239,7 @@ static int mxs_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
 	return !(dir & mask);
 }
 
-static struct platform_device_id mxs_gpio_ids[] = {
+static const struct platform_device_id mxs_gpio_ids[] = {
 	{
 		.name = "imx23-gpio",
 		.driver_data = IMX23_GPIO,

drivers/gpio/gpio-ts5500.c

@@ -440,7 +440,7 @@ static int ts5500_dio_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct platform_device_id ts5500_dio_ids[] = {
+static const struct platform_device_id ts5500_dio_ids[] = {
 	{ "ts5500-dio1", TS5500_DIO1 },
 	{ "ts5500-dio2", TS5500_DIO2 },
 	{ "ts5500-dio-lcd", TS5500_LCD },