devres: allow const resource arguments

devm_ioremap_resource() does not currently take 'const' arguments,
which results in a warning from the first driver trying to do it
anyway:

drivers/gpio/gpio-amd-fch.c: In function 'amd_fch_gpio_probe':
drivers/gpio/gpio-amd-fch.c:171:49: error: passing argument 2 of 'devm_ioremap_resource' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores);
                                                 ^~~~~~~~~~~~~~~~~~~

Change the prototype to allow it, as there is no real reason not to.

Fixes: 9bb2e0452508 ("gpio: amd: Make resource struct const")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20190628150049.1108048-1-arnd@arndb.deAcked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviwed-By: Enrico Weigelt <info@metux.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/device.h

@@ -704,7 +704,8 @@ extern unsigned long devm_get_free_pages(struct device *dev,
 					 gfp_t gfp_mask, unsigned int order);
 extern void devm_free_pages(struct device *dev, unsigned long addr);
 
-void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
+void __iomem *devm_ioremap_resource(struct device *dev,
+				    const struct resource *res);
 
 void __iomem *devm_of_iomap(struct device *dev,
 			    struct device_node *node, int index,

lib/devres.c

@@ -131,7 +131,8 @@ EXPORT_SYMBOL(devm_iounmap);
  *	if (IS_ERR(base))
  *		return PTR_ERR(base);
  */
-void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
+void __iomem *devm_ioremap_resource(struct device *dev,
+				    const struct resource *res)
 {
 	resource_size_t size;
 	void __iomem *dest_ptr;