MIPS: call set_cpu_online() on cpu being brought up with irq disabled

To prevent a problem as commit 5fbd036b [sched: Cleanup cpu_active madness]
and commit 2baab4e9 [sched: Fix select_fallback_rq() vs cpu_active/cpu_online]
try to resolve, move set_cpu_online() to the brought up CPU and with irq
disabled.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: David Daney <david.daney@cavium.com>
Acked-by: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/3851/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/smp.c

@@ -122,6 +122,8 @@ asmlinkage __cpuinit void start_secondary(void)
 
 	notify_cpu_starting(cpu);
 
+	set_cpu_online(cpu, true);
+
 	set_cpu_sibling_map(cpu);
 
 	cpu_set(cpu, cpu_callin_map);
@@ -197,8 +199,6 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 	while (!cpu_isset(cpu, cpu_callin_map))
 		udelay(100);
 
-	set_cpu_online(cpu, true);
-
 	return 0;
 }