Add defines needed to export SMBIOS serial numbers

Some defines needed for exporting serial numbers from the SMBIOS were
missed during integration of SMBIOS support in the EFI boot loader (r281138).
This is needed for getting the hostid set from the system hardware UUID.

PR: 206031
Submitted by: Thomas Eberhardt <sneakywumpus@gmail.com>
MFC after: 1 week