ARM: hisi: fix building without CONFIG_HOTPLUG_CPU

The hisi SMP code always uses the hi3xxx_set_cpu() function
defined in the hotplug.c file, so we cannot build without
this when CONFIG_SMP is enabled. This patch slightly restructures
the code so we always build the parts of hotplug.c that we need
but just leave out the CPU disable logic if CONFIG_HOTPLUG_CPU
is turned off.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>

arch/arm/mach-hisi/Makefile

@@ -3,5 +3,4 @@
 #
 
 obj-y	+= hisilicon.o
-obj-$(CONFIG_SMP)		+= platsmp.o
-obj-$(CONFIG_HOTPLUG_CPU)	+= hotplug.o
+obj-$(CONFIG_SMP)		+= platsmp.o hotplug.o

arch/arm/mach-hisi/hotplug.c

@@ -178,6 +178,7 @@ static inline void cpu_enter_lowpower(void)
 	  : "cc");
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
 void hi3xxx_cpu_die(unsigned int cpu)
 {
 	cpu_enter_lowpower();
@@ -198,3 +199,4 @@ int hi3xxx_cpu_kill(unsigned int cpu)
 	hi3xxx_set_cpu(cpu, false);
 	return 1;
 }
+#endif