[SPARC64]: Fix sparse warnings in arch/sparc64/kernel/irq.c

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/asm-sparc64/irq.h b/include/asm-sparc64/irq.h
index 30cb76b..0bb9bf5 100644
--- a/include/asm-sparc64/irq.h
+++ b/include/asm-sparc64/irq.h
@@ -64,6 +64,7 @@
 extern void virt_irq_free(unsigned int virt_irq);
 #endif
 
+extern void __init init_IRQ(void);
 extern void fixup_irqs(void);
 
 static inline void set_softint(unsigned long bits)