x86: Correct a build warning in x86 tables

There is a build warning for three x86 boards since
write_smbios_table_wrapper() is not used. Fix it.

Fixes: e824cf3f (smbios: Allow compilation on 64bit systems)
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Graf <agraf@suse.de>