irqchip/ativic32: Constify irq_domain_ops

This is passed to irq_domain_add_linear(), which accepts a pointer
to a const structure.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200714173857.477422-1-masahiroy@kernel.org

drivers/irqchip/irq-ativic32.c

@@ -92,7 +92,7 @@ static int ativic32_irq_domain_map(struct irq_domain *id, unsigned int virq,
 	return 0;
 }
 
-static struct irq_domain_ops ativic32_ops = {
+static const struct irq_domain_ops ativic32_ops = {
 	.map = ativic32_irq_domain_map,
 	.xlate = irq_domain_xlate_onecell
 };