EDAC, altera: Constify irq_domain_ops

struct irq_domain_ops is not modified, so it can be made const.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170524133505.1233-1-tklauser@distanz.chSigned-off-by: NBorislav Petkov <bp@suse.de>

drivers/edac/altera_edac.c

@@ -1839,7 +1839,7 @@ static int a10_eccmgr_irqdomain_map(struct irq_domain *d, unsigned int irq,
 	return 0;
 }
 
-static struct irq_domain_ops a10_eccmgr_ic_ops = {
+static const struct irq_domain_ops a10_eccmgr_ic_ops = {
 	.map = a10_eccmgr_irqdomain_map,
 	.xlate = irq_domain_xlate_twocell,
 };