irqchip: Constify irq_domain_ops

The irq_domain_ops are not modified by the driver and the irqdomain core
code accepts pointer to a const data.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Link: http://lkml.kernel.org/r/1430139264-4362-2-git-send-email-k.kozlowski.k@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/irqchip/irq-armada-370-xp.c

@@ -409,7 +409,7 @@ static struct notifier_block mpic_cascaded_cpu_notifier = {
 };
 #endif /* CONFIG_SMP */
 
-static struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
+static const struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
 	.map = armada_370_xp_mpic_irq_map,
 	.xlate = irq_domain_xlate_onecell,
 };