microblaze: use early_init_dt_scan

Convert microblaze to use new early_init_dt_scan function.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Michal Simek <monstr@monstr.eu>
Cc: microblaze-uclinux@itee.uq.edu.au

arch/microblaze/kernel/setup.c

@@ -50,7 +50,7 @@ char cmd_line[COMMAND_LINE_SIZE] __attribute__ ((section(".data")));
 
 void __init setup_arch(char **cmdline_p)
 {
-	*cmdline_p = cmd_line;
+	*cmdline_p = boot_command_line;
 
 	console_verbose();