arm64: Move cpu_die_early to smp.c

This patch moves cpu_die_early to smp.c, where it fits better.
No functional changes, except for adding the necessary checks
for CONFIG_HOTPLUG_CPU.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index b93eb33..51913be 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -77,6 +77,7 @@
 
 extern void __cpu_die(unsigned int cpu);
 extern void cpu_die(void);
+extern void cpu_die_early(void);
 
 static inline void cpu_park_loop(void)
 {