arch/mips/pci: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6349/

arch/mips/pci/pci-rt3883.c

@@ -436,9 +436,6 @@ static int rt3883_pci_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -EINVAL;
-
 	rpc->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(rpc->base))
 		return PTR_ERR(rpc->base);