thermal: brcmstb_thermal: Restructure interrupt registration

If we are successful grabbing the interrupt resource, then register an
interrupt handler, this makes it easier to support the interrupt as
being optional, which is it for 7216.

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200114190607.29339-6-f.fainelli@gmail.com

drivers/thermal/broadcom/brcmstb_thermal.c

@@ -343,16 +343,15 @@ static int brcmstb_thermal_probe(struct platform_device *pdev)
 	priv->thermal = thermal;
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		dev_err(&pdev->dev, "could not get IRQ\n");
-		return irq;
-	}
-	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
-					brcmstb_tmon_irq_thread, IRQF_ONESHOT,
-					DRV_NAME, priv);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
-		return ret;
+	if (irq >= 0) {
+		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+						brcmstb_tmon_irq_thread,
+						IRQF_ONESHOT,
+						DRV_NAME, priv);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
+			return ret;
+		}
 	}
 
 	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");