VL805 Flash SPI Bus Programmer Support

[Neil Armstrong]

Hi All,

Following Carl-Daniel Hailfinger's work on supporting the VL805 PCIe-USB3 Controller SPI bus at [1],
I pushed a cleaned, tested and fixed version on gerrit.

I had someone successfully testing support on it's own HW, but now it lacks proper review.
I'll be happy to fix the code to have it merged in the flashrom tree.

Best Regards,
Neil

[1] https://www.mail-archive.com/[e-mail]/msg14389.html
[2] https://review.coreboot.org/c/flashrom/+/50264