gpio: max77620: Make regmap_irq_chip const

Make the structure const as it is only passed to the function
devm_regmap_add_irq_chip having the corresponding argument as const.
Done using Coccinelle.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-max77620.c

@@ -82,7 +82,7 @@ static const struct regmap_irq max77620_gpio_irqs[] = {
 	},
 };
 
-static struct regmap_irq_chip max77620_gpio_irq_chip = {
+static const struct regmap_irq_chip max77620_gpio_irq_chip = {
 	.name = "max77620-gpio",
 	.irqs = max77620_gpio_irqs,
 	.num_irqs = ARRAY_SIZE(max77620_gpio_irqs),