Romulus to use Virtual PNOR

[Lei YU]

> What's the problem with version and image verification?

By that, I mean there is no service on Romulus to implement the interface of
/xyz/openbmc_project/Software/Version.interface.yaml and no pnor code's
verification during code update as how Witherspoon does.

> The installed PNOR reports its version via IPMI FRU now, so we know the installed version.
Great! Could you kindly let me know how do you implement this?