[S390] fix mismatch in summation of I/O IRQ statistics

Current IRQ statistics support does not show detail counts for I/O
interrupts which are processed internally only. The result is a
summation count which is way off such as this one:

           CPU0       CPU1       CPU2
I/O:       1331        710        442
[...]
QAI:         15         16         16   [I/O] QDIO Adapter Interrupt
QDI:          1          0          0   [I/O] QDIO Interrupt
DAS:        706        645        381   [I/O] DASD
C15:         26         10          0   [I/O] 3215
C70:          0          0          0   [I/O] 3270
TAP:          0          0          0   [I/O] Tape
VMR:          0          0          0   [I/O] Unit Record Devices
LCS:          0          0          0   [I/O] LCS
CLW:          0          0          0   [I/O] CLAW
CTC:          0          0          0   [I/O] CTC
APB:          0          0          0   [I/O] AP Bus

Fix this by moving I/O interrupt accounting into the common I/O layer.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 694464c..934458a 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -9,7 +9,6 @@
  *	      Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>
  */
 
-#include <linux/kernel_stat.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kdev_t.h>
@@ -362,7 +361,6 @@
 	int cstat, dstat;
 	int count;
 
-	kstat_cpu(smp_processor_id()).irqs[IOINT_C15]++;
 	raw = dev_get_drvdata(&cdev->dev);
 	req = (struct raw3215_req *) intparm;
 	cstat = irb->scsw.cmd.cstat;
@@ -776,6 +774,7 @@
 	.freeze		= &raw3215_pm_stop,
 	.thaw		= &raw3215_pm_start,
 	.restore	= &raw3215_pm_start,
+	.int_class	= IOINT_C15,
 };
 
 #ifdef CONFIG_TN3215_CONSOLE