nvk: driconf option to override vendor id
What does this MR do and why?
Some games match on the vendor ID and then check if the driver version is at least a specific version. The nvidia driver versions are much higher than mesa's. Some games just warn about the "old" driver version. Others refuse to start.
This MR adds support for the existing driconf option force_vk_vendor
. A section for NVK is added and configs for Baldur's Gate 3 and X4 Foundations.