pinctrl: nuvoton: npcm7xx: constify copied structure

The npcmgpio_irqchip structure is only copied into another
structure, so make it const.

The opportunity for this change was found using Coccinelle.

Signed-off-by: Julia Lawall <[e-mail]>

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c

···
 	return 0;
 }
 
-static struct irq_chip npcmgpio_irqchip = {
+static const struct irq_chip npcmgpio_irqchip = {
 	.name = "NPCM7XX-GPIO-IRQ",
 	.irq_ack = npcmgpio_irq_ack,
 	.irq_unmask = npcmgpio_irq_unmask,