[S390] irq: have detailed statistics for interrupt types

Up to now /proc/interrupts only has statistics for external and i/o
interrupts but doesn't split up them any further.
This patch adds a line for every single interrupt source so that it
is possible to easier tell what the machine is/was doing.
Part of the output now looks like this;

           CPU0       CPU2       CPU4
EXT:       3898       4232       2305
I/O:        782        315        245
CLK:       1029       1964        727   [EXT] Clock Comparator
IPI:       2868       2267       1577   [EXT] Signal Processor
TMR:          0          0          0   [EXT] CPU Timer
TAL:          0          0          0   [EXT] Timing Alert
PFL:          0          0          0   [EXT] Pseudo Page Fault
[...]
NMI:          0          1          1   [NMI] Machine Checks

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 1995c17..fab8843 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -8,6 +8,7 @@
  *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
  */
 
+#include <linux/kernel_stat.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/hardirq.h>
@@ -255,7 +256,7 @@
 	nmi_enter();
 	s390_idle_check(regs, S390_lowcore.mcck_clock,
 			S390_lowcore.mcck_enter_timer);
-
+	kstat_cpu(smp_processor_id()).irqs[NMI_NMI]++;
 	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
 	mcck = &__get_cpu_var(cpu_mcck);
 	umode = user_mode(regs);