genirq: Export irq_gc_noop()

In order to build drivers/irqchip/irq-bcm7120-l2.c as a module which
references irq_gc_noop(), we need to export it towards modules.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211020184859.2705451-10-f.fainelli@gmail.com

kernel/irq/generic-chip.c

@@ -25,6 +25,7 @@ static DEFINE_RAW_SPINLOCK(gc_lock);
 void irq_gc_noop(struct irq_data *d)
 {
 }
+EXPORT_SYMBOL_GPL(irq_gc_noop);
 
 /**
  * irq_gc_mask_disable_reg - Mask chip via disable register