rtc: wm831x: Add IRQF_ONESHOT flag

fix below issue reported by coccicheck
drivers/rtc/rtc-wm831x.c:436:7-32: ERROR: Threaded IRQ with no primary
handler requested without IRQF_ONESHOT
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20190711175615.GA13651@hari-Inspiron-1545Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-wm831x.c

@@ -435,7 +435,8 @@ static int wm831x_rtc_probe(struct platform_device *pdev)
 
 	ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL,
 				wm831x_alm_irq,
-				IRQF_TRIGGER_RISING, "RTC alarm",
+				IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+				"RTC alarm",
 				wm831x_rtc);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",