genirq/generic_chip: Export irq_unmap_generic_chip

Some irq controllers have to re-implement a private version for
irq_generic_chip_ops, because they have a different xlate to translate
hwirq. Export irq_unmap_generic_chip to allow reusing in drivers.
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1658314292-35346-5-git-send-email-lvjianmin@loongson.cn

include/linux/irq.h

@@ -1121,6 +1121,7 @@ int irq_gc_set_wake(struct irq_data *d, unsigned int on);
 /* Setup functions for irq_chip_generic */
 int irq_map_generic_chip(struct irq_domain *d, unsigned int virq,
 			 irq_hw_number_t hw_irq);
+void irq_unmap_generic_chip(struct irq_domain *d, unsigned int virq);
 struct irq_chip_generic *
 irq_alloc_generic_chip(const char *name, int nr_ct, unsigned int irq_base,
 		       void __iomem *reg_base, irq_flow_handler_t handler);

kernel/irq/generic-chip.c

@@ -431,7 +431,7 @@ int irq_map_generic_chip(struct irq_domain *d, unsigned int virq,
 	return 0;
 }
 
-static void irq_unmap_generic_chip(struct irq_domain *d, unsigned int virq)
+void irq_unmap_generic_chip(struct irq_domain *d, unsigned int virq)
 {
 	struct irq_data *data = irq_domain_get_irq_data(d, virq);
 	struct irq_domain_chip_generic *dgc = d->gc;