irq: export __set_irq_handler() and handle_level_irq()

Impact: build fix

ARM updates broke x86 allmodconfig builds:

 ERROR: "__set_irq_handler" [drivers/mfd/pcf50633-core.ko] undefined!
 ERROR: "handle_level_irq" [drivers/mfd/pcf50633-core.ko] undefined!
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/irq/chip.c

@@ -383,6 +383,7 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 out_unlock:
 	spin_unlock(&desc->lock);
 }
+EXPORT_SYMBOL_GPL(handle_level_irq);
 
 /**
  *	handle_fasteoi_irq - irq handler for transparent controllers
@@ -593,6 +594,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 	}
 	spin_unlock_irqrestore(&desc->lock, flags);
 }
+EXPORT_SYMBOL_GPL(__set_irq_handler);
 
 void
 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,