ARM: 7380/1: DT: do not add a zero-sized memory property

Some bootloaders are broken enough to expose an ATAG_MEM with
a null size. Converting such tag to a memory node leads to
an unbootable system.

Skip over zero sized ATAG_MEM to avoid this situation.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/boot/compressed/atags_to_fdt.c

@@ -77,6 +77,8 @@ int atags_to_fdt(void *atag_list, void *fdt, int total_space)
 		} else if (atag->hdr.tag == ATAG_MEM) {
 			if (memcount >= sizeof(mem_reg_property)/4)
 				continue;
+			if (!atag->u.mem.size)
+				continue;
 			mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.start);
 			mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.size);
 		} else if (atag->hdr.tag == ATAG_INITRD2) {