ARM: SMP: collect IPI and local timer IRQs for /proc/stat

The IPI and local timer interrupts weren't being properly accounted
for in /proc/stat.  Collect them from the irq_stat structure, and
return their sum.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h
index c52e250..89ad180 100644
--- a/arch/arm/include/asm/hardirq.h
+++ b/arch/arm/include/asm/hardirq.h
@@ -22,6 +22,14 @@
 #define __inc_irq_stat(cpu, member)	__IRQ_STAT(cpu, member)++
 #define __get_irq_stat(cpu, member)	__IRQ_STAT(cpu, member)
 
+#ifdef CONFIG_SMP
+u64 smp_irq_stat_cpu(unsigned int cpu);
+#else
+#define smp_irq_stat_cpu(cpu)	0
+#endif
+
+#define arch_irq_stat_cpu	smp_irq_stat_cpu
+
 #if NR_IRQS > 512
 #define HARDIRQ_BITS	10
 #elif NR_IRQS > 256