ARM: 6402/1: Don't send IPI in smp_send_stop if there's only one CPU

No need to send IPI if there's one CPU, especially when booting
systems with CONFIG_SMP_ON_UP that may not even support IPI.
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/smp.c

@@ -567,7 +567,8 @@ void smp_send_stop(void)
 {
 	cpumask_t mask = cpu_online_map;
 	cpu_clear(smp_processor_id(), mask);
-	send_ipi_message(&mask, IPI_CPU_STOP);
+	if (!cpus_empty(mask))
+		send_ipi_message(&mask, IPI_CPU_STOP);
 }
 
 /*