drivers/rtc/rtc-imxdi.c: add missing spin lock initialization

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Roland Stigge <stigge@antcom.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Roland Stigge <stigge@antcom.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-imxdi.c b/drivers/rtc/rtc-imxdi.c
index 891cd6c..4eed510 100644
--- a/drivers/rtc/rtc-imxdi.c
+++ b/drivers/rtc/rtc-imxdi.c
@@ -392,6 +392,8 @@
 	if (imxdi->ioaddr == NULL)
 		return -ENOMEM;
 
+	spin_lock_init(&imxdi->irq_lock);
+
 	imxdi->irq = platform_get_irq(pdev, 0);
 	if (imxdi->irq < 0)
 		return imxdi->irq;