x86, NUMA: rename srat_64.c to srat.c

Rename srat_64.c to srat.c.  This is to prepare for unification of
NUMA init paths between 32 and 64bit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>

arch/x86/mm/Makefile

@@ -24,7 +24,10 @@ obj-$(CONFIG_MMIOTRACE_TEST)	+= testmmiotrace.o
 
 obj-$(CONFIG_NUMA)		+= numa.o numa_$(BITS).o
 obj-$(CONFIG_AMD_NUMA)		+= amdtopology_64.o
-obj-$(CONFIG_ACPI_NUMA)		+= srat_$(BITS).o
+ifeq ($(CONFIG_ACPI_NUMA),y)
+obj-$(CONFIG_X86_64)		+= srat.o
+obj-$(CONFIG_X86_32)		+= srat_32.o
+endif
 obj-$(CONFIG_NUMA_EMU)		+= numa_emulation.o
 
 obj-$(CONFIG_HAVE_MEMBLOCK)		+= memblock.o