gpio: zevio: make gpio_chip const

Make this const as it is only used as a copy operation.
Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-zevio.c b/drivers/gpio/gpio-zevio.c
index e23ef7b..3926ce9 100644
--- a/drivers/gpio/gpio-zevio.c
+++ b/drivers/gpio/gpio-zevio.c
@@ -156,7 +156,7 @@
 	return -ENXIO;
 }
 
-static struct gpio_chip zevio_gpio_chip = {
+static const struct gpio_chip zevio_gpio_chip = {
 	.direction_input	= zevio_gpio_direction_input,
 	.direction_output	= zevio_gpio_direction_output,
 	.set			= zevio_gpio_set,