irq_domain/c6x: constify irq_domain structures

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Mark Salter <msalter@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 7275d80..f0783be 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -635,7 +635,7 @@
 	return 0;
 }
 
-struct irq_domain_ops gic_irq_domain_ops = {
+const struct irq_domain_ops gic_irq_domain_ops = {
 	.map = gic_irq_domain_map,
 	.xlate = gic_irq_domain_xlate,
 };