rtc: da9063: Make IRQ as optional

On some platforms (eg: RZ/{G2UL,Five} SMARC EVK), there is no IRQ
populated by default. Add irq optional support.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240105145344.204453-2-biju.das.jz@bp.renesas.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-da9063.c

@@ -485,25 +485,29 @@ static int da9063_rtc_probe(struct platform_device *pdev)
 		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc_dev->features);
 	}
 
-	irq_alarm = platform_get_irq_byname(pdev, "ALARM");
-	if (irq_alarm < 0)
+	irq_alarm = platform_get_irq_byname_optional(pdev, "ALARM");
+	if (irq_alarm >= 0) {
+		ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
+						da9063_alarm_event,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"ALARM", rtc);
+		if (ret)
+			dev_err(&pdev->dev,
+				"Failed to request ALARM IRQ %d: %d\n",
+				irq_alarm, ret);
+
+		ret = dev_pm_set_wake_irq(&pdev->dev, irq_alarm);
+		if (ret)
+			dev_warn(&pdev->dev,
+				 "Failed to set IRQ %d as a wake IRQ: %d\n",
+				 irq_alarm, ret);
+
+		device_init_wakeup(&pdev->dev, true);
+	}  else if (irq_alarm != -ENXIO) {
 		return irq_alarm;
-
-	ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
-					da9063_alarm_event,
-					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
-					"ALARM", rtc);
-	if (ret)
-		dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
-			irq_alarm, ret);
-
-	ret = dev_pm_set_wake_irq(&pdev->dev, irq_alarm);
-	if (ret)
-		dev_warn(&pdev->dev,
-			 "Failed to set IRQ %d as a wake IRQ: %d\n",
-			 irq_alarm, ret);
-
-	device_init_wakeup(&pdev->dev, true);
+	} else {
+		clear_bit(RTC_FEATURE_ALARM, rtc->rtc_dev->features);
+	}
 
 	return devm_rtc_register_device(rtc->rtc_dev);
 }