drm/mediatek: mtk_dpi: Use devm_platform_ioremap_resource()

Instead of the open-coded platform_get_resource, devm_ioremap_resource
switch to devm_platform_ioremap_resource(), also dropping the useless
struct resource pointer, which becomes unused.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Fei Shao <fshao@chromium.org>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230726082245.550929-6-angelogioacchino.delregno@collabora.com/Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -1007,7 +1007,6 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct mtk_dpi *dpi;
-	struct resource *mem;
 	int ret;
 
 	dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
@@ -1038,8 +1037,7 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 			dev_dbg(&pdev->dev, "Cannot find pinctrl active!\n");
 		}
 	}
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	dpi->regs = devm_ioremap_resource(dev, mem);
+	dpi->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(dpi->regs))
 		return dev_err_probe(dev, PTR_ERR(dpi->regs),
 				     "Failed to ioremap mem resource\n");