x86, mce: add MCE poll count to /proc/interrupts

Keep a count of the machine check polls (or CMCI events) in
/proc/interrupts.

Andi needs this for debugging, but it's also useful in general
to see what's going in by the kernel.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 1156dae..63abf3b 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -125,6 +125,7 @@
 int mce_available(struct cpuinfo_x86 *c);
 
 DECLARE_PER_CPU(unsigned, mce_exception_count);
+DECLARE_PER_CPU(unsigned, mce_poll_count);
 
 void mce_log_therm_throt_event(__u64 status);