amd-xgbe: Use platform_irq_count()

The AMD XGbE driver currently counts the number of interrupts assigned
to the device by inspecting the pdev->resource array. Since commit
a1a2b71 ("of/platform: Drop static setup of IRQ resource from DT
core") removed IRQs from this array, the driver now attempts to get all
interrupts from 1 to -1U and gives up probing once it reaches an invalid
interrupt index.

Obtain the number of IRQs with platform_irq_count() instead.

Fixes: a1a2b71 ("of/platform: Drop static setup of IRQ resource from DT core")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20220609161457.69614-1-jean-philippe@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Jean-Philippe Brucker

drivers/net/ethernet/amd/xgbe/xgbe-platform.c

@@ -338,7 +338,7 @@ static int xgbe_platform_probe(struct platform_device *pdev)
 		 *   the PHY resources listed last
 		 */
 		phy_memnum = xgbe_resource_count(pdev, IORESOURCE_MEM) - 3;
-		phy_irqnum = xgbe_resource_count(pdev, IORESOURCE_IRQ) - 1;
+		phy_irqnum = platform_irq_count(pdev) - 1;
 		dma_irqnum = 1;
 		dma_irqend = phy_irqnum;
 	} else {
@@ -348,7 +348,7 @@ static int xgbe_platform_probe(struct platform_device *pdev)
 		phy_memnum = 0;
 		phy_irqnum = 0;
 		dma_irqnum = 1;
-		dma_irqend = xgbe_resource_count(pdev, IORESOURCE_IRQ);
+		dma_irqend = platform_irq_count(pdev);
 	}
 
 	/* Obtain the mmio areas for the device */