mtd: rawnand: omap_elm: Use platform_get_irq() to get the interrupt

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211221212609.31290-2-prabhakar.mahadev-lad.rj@bp.renesas.com

drivers/mtd/nand/raw/omap_elm.c

@@ -384,8 +384,8 @@ static irqreturn_t elm_isr(int this_irq, void *dev_id)
 static int elm_probe(struct platform_device *pdev)
 {
 	int ret = 0;
-	struct resource *irq;
 	struct elm_info *info;
+	int irq;
 
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 	if (!info)
@@ -393,20 +393,18 @@ static int elm_probe(struct platform_device *pdev)
 
 	info->dev = &pdev->dev;
 
-	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq) {
-		dev_err(&pdev->dev, "no irq resource defined\n");
-		return -ENODEV;
-	}
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	info->elm_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(info->elm_base))
 		return PTR_ERR(info->elm_base);
 
-	ret = devm_request_irq(&pdev->dev, irq->start, elm_isr, 0,
-			pdev->name, info);
+	ret = devm_request_irq(&pdev->dev, irq, elm_isr, 0,
+			       pdev->name, info);
 	if (ret) {
-		dev_err(&pdev->dev, "failure requesting %pr\n", irq);
+		dev_err(&pdev->dev, "failure requesting %d\n", irq);
 		return ret;
 	}