genirq: Export irq_gc_{unmask_enable,mask_disable}_reg

In order to allow drivers/irqchip/irq-brcmstb-l2.c to be built as a
module we need to export: irq_gc_unmask_enable_reg() and
irq_gc_mask_disable_reg().

Signed-off-by: Florian Fainelli <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

kernel/irq/generic-chip.c

···
 	*ct->mask_cache &= ~mask;
 	irq_gc_unlock(gc);
 }
+EXPORT_SYMBOL_GPL(irq_gc_mask_disable_reg);
 
 /**
  * irq_gc_mask_set_bit - Mask chip via setting bit in mask register
···
 	*ct->mask_cache |= mask;
 	irq_gc_unlock(gc);
 }
+EXPORT_SYMBOL_GPL(irq_gc_unmask_enable_reg);
 
 /**
  * irq_gc_ack_set_bit - Ack pending interrupt via setting bit