Fine-tune the V-link bus between K8T890 and VT8237R and set

Fine-tune the V-link bus between K8T890 and VT8237R and set
it to 8X transfer rate (up to 1066 MB/s) similar code placed here would be
needed for VT8237A/S etc. Using VIA recommended values despite they are for
K8T890CF, this is K8T890CE (still dont know what is exactly different).

This patch enables the parity error reporting on V-Link, so it enables NMI
generation for the SERR# errors. The NMI may not be generated, maybe port
61h needs some tuning too.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2958 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1