powerpc: make irq_choose_cpu() available to all PIC drivers

Move irq_choose_cpu() into arch/powerpc/kernel/irq.c so that it can be used
by other PIC drivers.  The function is not MPIC-specific.

Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 1bff591..c57a28e 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -330,5 +330,7 @@
 			   struct thread_info *tp, void *func);
 extern void do_IRQ(struct pt_regs *regs);
 
+int irq_choose_cpu(const struct cpumask *mask);
+
 #endif /* _ASM_IRQ_H */
 #endif /* __KERNEL__ */