[PATCH -next] s390/idle: Add missing EXPORT_SYMBOL()

[Heiko Carstens <hca@linux.ibm.com>]

Uwe Kleine-König reported this build breakage caused by a recent commit
which provides arch specific kcpustat_field_idle()/kcpustat_field_iowait()
functions:

ERROR: modpost: "arch_kcpustat_field_idle" [drivers/leds/trigger/ledtrig-activity.ko] undefined!
ERROR: modpost: "arch_kcpustat_field_iowait" [drivers/leds/trigger/ledtrig-activity.ko] undefined!

Fix this by adding the missing EXPORT_SYMBOL().

Fixes: 670e057744e0 ("s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait()")
Reported-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Closes: https://lore.kernel.org/r/ajKsG0JP6qTssQBX@monoceros
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 arch/s390/kernel/idle.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 7f7851c001e0..6da8ee22a1d5 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/cpu.h>
 #include <trace/events/power.h>
+#include <linux/export.h>
 #include <asm/cpu_mf.h>
 #include <asm/cputime.h>
 #include <asm/idle.h>
@@ -83,11 +84,13 @@ u64 arch_kcpustat_field_idle(int cpu)
 {
 	return arch_cpu_idle_time(cpu, CPUTIME_IDLE, !nr_iowait_cpu(cpu));
 }
+EXPORT_SYMBOL(arch_kcpustat_field_idle);
 
 u64 arch_kcpustat_field_iowait(int cpu)
 {
 	return arch_cpu_idle_time(cpu, CPUTIME_IOWAIT, nr_iowait_cpu(cpu));
 }
+EXPORT_SYMBOL(arch_kcpustat_field_iowait);
 
 void account_idle_time_irq(void)
 {
-- 
2.53.0