x86: Move smbios generation into arch independent directory

We will need the SMBIOS generation function on ARM as well going forward,
so let's move it into a non arch specific location.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/lib/tables.c b/arch/x86/lib/tables.c
index 9ee6b5e..e62705a 100644
--- a/arch/x86/lib/tables.c
+++ b/arch/x86/lib/tables.c
@@ -5,9 +5,9 @@
  */
 
 #include <common.h>
+#include <smbios.h>
 #include <asm/sfi.h>
 #include <asm/mpspec.h>
-#include <asm/smbios.h>
 #include <asm/tables.h>
 #include <asm/acpi_table.h>
 #include <asm/coreboot_tables.h>