sparseirq: move __weak symbols into separate compilation unit

GCC has a bug with __weak alias functions: if the functions are in
the same compilation unit as their call site, GCC can decide to
inline them - and thus rob the linker of the opportunity to override
the weak alias with the real thing.

So move all the IRQ handling related __weak symbols to kernel/irq/chip.c.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 777f89e..d9a3703 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -467,4 +467,10 @@
 
 int show_interrupts(struct seq_file *p, void *v);
 
+struct irq_desc;
+
+extern int early_irq_init(void);
+extern int arch_early_irq_init(void);
+extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
+
 #endif
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 0e40af4..d64a6d4 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -193,9 +193,6 @@
 	const char		*name;
 } ____cacheline_internodealigned_in_smp;
 
-extern int early_irq_init(void);
-extern int arch_early_irq_init(void);
-extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
 extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
 					struct irq_desc *desc, int cpu);
 extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);