MIPS: ralink: copy the commandline from the devicetree

This is a regression caused by:
commit afb46f7996
Author: Rob Herring <robh@kernel.org>
Date:   Wed Apr 2 19:07:24 2014 -0500
mips: ralink: convert to use unflatten_and_copy_device_tree

Make the of init code reuse the cmdline defined inside the dts.

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/8008/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ralink/of.c

@@ -74,6 +74,8 @@ void __init plat_mem_setup(void)
 	 */
 	__dt_setup_arch(__dtb_start);
 
+	strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+
 	of_scan_flat_dt(early_init_dt_find_memory, NULL);
 	if (memory_dtb)
 		of_scan_flat_dt(early_init_dt_scan_memory, NULL);