drivers: provide devm_platform_ioremap_resource()

There are currently 1200+ instances of using platform_get_resource()
and devm_ioremap_resource() together in the kernel tree.

This patch wraps these two calls in a single helper. Thanks to that
we don't have to declare a local variable for struct resource * and can
omit the redundant argument for resource type. We also have one
function call less.

Signed-off-by: Bartosz Golaszewski <[e-mail]>
Acked-by: Greg Kroah-Hartman <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/base/platform.c

···
 EXPORT_SYMBOL_GPL(platform_get_resource);
 
 /**
+ * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
+ *				    device
+ *
+ * @pdev: platform device to use both for memory resource lookup as well as
+ *        resource managemend
+ * @index: resource index
+ */
+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);
+}
+EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
+
+/**
  * platform_get_irq - get an IRQ for a device
  * @dev: platform device
  * @num: IRQ number index

include/linux/platform_device.h

···
 extern void arch_setup_pdev_archdata(struct platform_device *);
 extern struct resource *platform_get_resource(struct platform_device *,
 					      unsigned int, unsigned int);
+extern void __iomem *
+devm_platform_ioremap_resource(struct platform_device *pdev,
+			       unsigned int index);
 extern int platform_get_irq(struct platform_device *, unsigned int);
 extern int platform_irq_count(struct platform_device *);
 extern struct resource *platform_get_resource_byname(struct platform_device *,