I'd like to avoid pushing more stuff into the mainboard code. I'll start from your code, but try to keep the rsdp2 stuff contained, so please hold off with committing for a while (to avoid touching all those of mainboard files). Of course, if I don't follow up, go ahead - it's better than not doing it.
If you factor out the generic parts of the Kontron acpi_write_tables, I'll factor out the other boards so we can have one function. Then it will make more sense to add rsdp2.
Thanks, Myles