ARM: Allow dumping of device tree

By calling qemu_devtree_dumpdtb near the end of load_dtb.
Signed-off-by: NJohn Rigby <john.rigby@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/arm/boot.c

@@ -303,6 +303,7 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
             fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
         }
     }
+    qemu_devtree_dumpdtb(fdt, size);
 
     cpu_physical_memory_write(addr, fdt, size);