irqchip/i8259: Constify irq_domain_ops

struct irq_domain_ops is not modified, so it can be made const.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/irq-i8259.c

@@ -307,7 +307,7 @@ static int i8259A_irq_domain_map(struct irq_domain *d, unsigned int virq,
 	return 0;
 }
 
-static struct irq_domain_ops i8259A_ops = {
+static const struct irq_domain_ops i8259A_ops = {
 	.map = i8259A_irq_domain_map,
 	.xlate = irq_domain_xlate_onecell,
 };