Script updates DMI for pcbios, disregards EFI / UEFI

[shoffmeister]

The script is currently hardcoded to write the DMI information into pcbios.

This results in VirtualBox to refuse starting the virtual machine with the rather cryptic BootDevice0 not found if EFI boot mode is active for the VM.

A manual search and replace over the vbox file, replacing pcbios with efi (see at the top of https://www.virtualbox.org/manual/ch09.html#changedmi) makes VirtualBox start the virtual machine without complaints.

Alas, this does still not fix booting the physical Windows 10 Home on my Dell XPS 9360 (which has its Windows 10 licence activated in the BIOS).