irqchip/ts4800: Make ts4800_ic_ops static const

ts4800_ic_ops is only referenced in this driver, so make it static.
In additional, it's never get modified thus also make it const.

Signed-off-by: Axel Lin <[e-mail]>
Reviewed-by: Damien Riegel <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Jason Cooper <[e-mail]>

drivers/irqchip/irq-ts4800.c

···
 	return 0;
 }
 
-struct irq_domain_ops ts4800_ic_ops = {
+static const struct irq_domain_ops ts4800_ic_ops = {
 	.map = ts4800_irqdomain_map,
 	.xlate = irq_domain_xlate_onecell,
 };