driver core: platform: Reimplement devm_platform_ioremap_resource

Reimplement devm_platform_ioremap_resource() by calling
devm_platform_ioremap_and_get_resource() with res = NULL to
simplify the code.
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Link: https://lore.kernel.org/r/20200323160612.17277-6-zhengdejin5@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/platform.c

@@ -95,10 +95,7 @@ EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource);
 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
 					     unsigned int index)
 {
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
-	return devm_ioremap_resource(&pdev->dev, res);
+	return devm_platform_get_and_ioremap_resource(pdev, index, NULL);
 }
 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);