arm64: Remove duplicate inclusion of mmu_context.h in smp.c

asm/mmu_context.h was included twice.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/smp.c

@@ -46,7 +46,6 @@
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
 #include <asm/ptrace.h>
-#include <asm/mmu_context.h>
 
 /*
  * as from 2.5, kernels no longer have an init_tasks structure