genirq: Remove export of irq_map_generic_chip()

No module users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/irq/generic-chip.c

@@ -409,7 +409,6 @@ int irq_map_generic_chip(struct irq_domain *d, unsigned int virq,
 	irq_modify_status(virq, dgc->irq_flags_to_clear, dgc->irq_flags_to_set);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(irq_map_generic_chip);
 
 struct irq_domain_ops irq_generic_chip_ops = {
 	.map	= irq_map_generic_chip,