x86: Move acpi_s3.h to a common location

At present this hedaer is only available on x86. To allow sandbox to use
it for testing, move it to a common location.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index 290ee08..9ee4b02 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -19,13 +19,13 @@
  */
 
 #include <common.h>
+#include <acpi_s3.h>
 #include <command.h>
 #include <dm.h>
 #include <errno.h>
 #include <malloc.h>
 #include <syscon.h>
 #include <asm/acpi.h>
-#include <asm/acpi_s3.h>
 #include <asm/acpi_table.h>
 #include <asm/control_regs.h>
 #include <asm/coreboot_tables.h>