rtc: mxc_v2: Replace spin_lock_irqsave with spin_lock in hard IRQ

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1612355981-6764-7-git-send-email-tanxiaofei@huawei.com

drivers/rtc/rtc-mxc_v2.c

@@ -74,13 +74,12 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 	struct device *dev = dev_id;
 	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
 	void __iomem *ioaddr = pdata->ioaddr;
-	unsigned long flags;
 	u32 lp_status;
 	u32 lp_cr;
 
-	spin_lock_irqsave(&pdata->lock, flags);
+	spin_lock(&pdata->lock);
 	if (clk_enable(pdata->clk)) {
-		spin_unlock_irqrestore(&pdata->lock, flags);
+		spin_unlock(&pdata->lock);
 		return IRQ_NONE;
 	}
 
@@ -104,7 +103,7 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 
 	mxc_rtc_sync_lp_locked(dev, ioaddr);
 	clk_disable(pdata->clk);
-	spin_unlock_irqrestore(&pdata->lock, flags);
+	spin_unlock(&pdata->lock);
 	return IRQ_HANDLED;
 }