genirq/generic_chip: Export irq_gc_mask_disable_and_ack_set()

The recent conversion of brcmstb_l2_mask_and_ack() to
irq_gc_mask_disable_and_ack_set() missed that the driver can be built as a
module, but the generic function is not exported.

Add the missing export.

[ tglx: Converted it to a fix ]

Fixes: dd1f17a ("irqchip/irq-brcmstb-l2: Replace brcmstb_l2_mask_and_ack() by generic function")
Signed-off-by: Dr. David Alan Gilbert <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/all/[email protected]

Author: Dr. David Alan Gilbert

kernel/irq/generic-chip.c

@@ -162,6 +162,7 @@ void irq_gc_mask_disable_and_ack_set(struct irq_data *d)
 	irq_reg_writel(gc, mask, ct->regs.ack);
 	irq_gc_unlock(gc);
 }
+EXPORT_SYMBOL_GPL(irq_gc_mask_disable_and_ack_set);
 
 /**
  * irq_gc_eoi - EOI interrupt