nds32: Fix the dts pointer is not passed correctly issue.

We found that the original implementation will only use the built-in dtb
pointer instead of the pointer pass from bootloader. This bug is fixed
by this patch.
Signed-off-by: Greentime Hu <greentime@andestech.com>

arch/nds32/kernel/setup.c

@@ -278,7 +278,8 @@ static void __init setup_memory(void)
 
 void __init setup_arch(char **cmdline_p)
 {
-	early_init_devtree( __dtb_start);
+	early_init_devtree(__atags_pointer ? \
+		phys_to_virt(__atags_pointer) : __dtb_start);
 
 	setup_cpuinfo();