mfd: fsl-imx25-tsadc: 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: Lee Jones <lee.jones@linaro.org>

drivers/mfd/fsl-imx25-tsadc.c

@@ -59,7 +59,7 @@ static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
 	return 0;
 }
 
-static struct irq_domain_ops mx25_tsadc_domain_ops = {
+static const struct irq_domain_ops mx25_tsadc_domain_ops = {
 	.map = mx25_tsadc_domain_map,
 	.xlate = irq_domain_xlate_onecell,
 };