[ARM] SMP: don't set cpu_*_map in smp_prepare_boot_cpu

The recent addition of boot_cpu_init() implements the initialisation
of the online, present and possible cpu maps for the boot CPU, so
there is no reason to duplicate this in the architecture
smp_prepare_boot_cpu() hook.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/smp.c

@@ -337,9 +337,6 @@ void __init smp_prepare_boot_cpu(void)
 	unsigned int cpu = smp_processor_id();
 
 	per_cpu(cpu_data, cpu).idle = current;
-
-	cpu_set(cpu, cpu_present_map);
-	cpu_set(cpu, cpu_online_map);
 }
 
 static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)