[S390] ap bus: add support for irq statistics

Add support for AP Bus I/O interrupt statistics in /proc/interrupts.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h
index 8c79f94..db14a31 100644
--- a/arch/s390/include/asm/irq.h
+++ b/arch/s390/include/asm/irq.h
@@ -25,6 +25,7 @@
 	IOINT_LCS,
 	IOINT_CLW,
 	IOINT_CTC,
+	IOINT_APB,
 	NMI_NMI,
 	NR_IRQS,
 };