ARM: 7700/2: Make cpu_init() notrace

On resume from CPU power down any trace hooks enabled in cpu_init()
will get called before that function has done set_my_cpu_offset(),
so any use of per-cpu variables by trace hook code will cause bad
things to happen. Prevent this by marking the function notrace.

This fixes lockups/crashes seen when enabling function tracer on TC2
with the not yet mainlined cpuidle driver.
Signed-off-by: NJon Medhurst <tixy@linaro.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/setup.c

@@ -389,7 +389,7 @@ static void __init feat_v6_fixup(void)
  *
  * cpu_init sets up the per-CPU stacks.
  */
-void cpu_init(void)
+void notrace cpu_init(void)
 {
 	unsigned int cpu = smp_processor_id();
 	struct stack *stk = &stacks[cpu];