smbios: Move the rest of the SMBIOS2 code

Move all of this logic into the else clause, since it will not be used
for SMBIOS3

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>