dt-schema u-boot,config node

[Michal Simek]

Hi Simon,

We just got a request to setup bootscript address via DT that's why I am trying
to refresh my mind how to do it.
I know that u-boot,config have been merged to via this pull request
https://github.com/devicetree-org/dt-schema/pull/62

I also grep all your branches in u-boot-dm tree but I can't see it to be used
anywhere. What's the current state on it?

I expect all of these options doc/device-tree-bindings/config.txt
should be converted to u-boot,config node.

Thanks,
Michal