rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc_isr()

The TOY_MATCH0_REG should be cleared to 0 in the RTC interrupt handler,
otherwise the interrupt cannot be cleared, which will cause the
loongson_rtc_isr() to be triggered multiple times.

The previous code cleared TOY_MATCH0_REG in the loongson_rtc_handler(),
which is an ACPI interrupt. This did not prevent loongson_rtc_isr()
from being triggered multiple times.

This commit moves the clearing of TOY_MATCH0_REG to the
loongson_rtc_isr() to ensure that the interrupt is properly cleared.

Fixes: 1b733a9ebc ("rtc: Add rtc driver for the Loongson family chips")
Signed-off-by: Ming Wang <wangming01@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Keguang Zhang <keguang.zhang@gmail.com> # on LS1B
Tested-by: Keguang Zhang <keguang.zhang@gmail.com>
Link: https://lore.kernel.org/r/20241205114307.1891418-1-wangming01@loongson.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-loongson.c

@@ -114,6 +114,13 @@ static irqreturn_t loongson_rtc_isr(int irq, void *id)
 	struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
 
 	rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
+
+	/*
+	 * The TOY_MATCH0_REG should be cleared 0 here,
+	 * otherwise the interrupt cannot be cleared.
+	 */
+	regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
+
 	return IRQ_HANDLED;
 }
 
@@ -131,11 +138,7 @@ static u32 loongson_rtc_handler(void *id)
 	writel(RTC_STS, priv->pm_base + PM1_STS_REG);
 	spin_unlock(&priv->lock);
 
-	/*
+	return ACPI_INTERRUPT_HANDLED;
-	 * The TOY_MATCH0_REG should be cleared 0 here,
-	 * otherwise the interrupt cannot be cleared.
-	 */
-	return regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
 }
 
 static int loongson_rtc_set_enabled(struct device *dev)