x86: rename tlb_64.c to tlb.c

Impact: file rename

tlb_64.c is now the tlb code for both 32 and 64.  Rename it to tlb.c.
Signed-off-by: NTejun Heo <tj@kernel.org>

arch/x86/kernel/Makefile

@@ -58,7 +58,7 @@ obj-$(CONFIG_PCI)		+= early-quirks.o
 apm-y				:= apm_32.o
 obj-$(CONFIG_APM)		+= apm.o
 obj-$(CONFIG_X86_SMP)		+= smp.o
-obj-$(CONFIG_X86_SMP)		+= smpboot.o tsc_sync.o ipi.o tlb_64.o
+obj-$(CONFIG_X86_SMP)		+= smpboot.o tsc_sync.o ipi.o tlb.o
 obj-$(CONFIG_X86_32_SMP)	+= smpcommon.o
 obj-$(CONFIG_X86_64_SMP)	+= tsc_sync.o smpcommon.o
 obj-$(CONFIG_X86_TRAMPOLINE)	+= trampoline_$(BITS).o