bus: mvebu-mbus: Fix optional pcie-mem/io-aperture properties

If the property was not specified then the returned resource had a
resource_size(..) == 1, rather than 0. The PCI-E driver checks for 0 so it
blindly continues on with a corrupted resource.

The regression was introduced into v3.12 by:

  11be6547 PCI: mvebu: Adapt to the new device tree layout
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

drivers/bus/mvebu-mbus.c

@@ -865,11 +865,13 @@ static void __init mvebu_mbus_get_pcie_resources(struct device_node *np,
 	int ret;
 
 	/*
-	 * These are optional, so we clear them and they'll
-	 * be zero if they are missing from the DT.
+	 * These are optional, so we make sure that resource_size(x) will
+	 * return 0.
 	 */
 	memset(mem, 0, sizeof(struct resource));
+	mem->end = -1;
 	memset(io, 0, sizeof(struct resource));
+	io->end = -1;
 
 	ret = of_property_read_u32_array(np, "pcie-mem-aperture", reg, ARRAY_SIZE(reg));
 	if (!ret) {