[U-Boot] new board with common code

[Fabian Cenedese]

Hi

I'm adding a new board. It's very similar to freescale's P2020DS, that's
why I used this code as starting point. The problem is now that it still
uses some code from board/freescale/common. At the first try this
didn't get built and therefore I get link errors. What's the preferred
way in this case?

- Is it allowed to use sources inside another board/vendor?
- Is it better to link to it or should I just copy the files into our
  vendor or board directory?
- If it's okay to link to objects from another place, how can I
  adjust the makefiles/config.mk so the freescale's common
  lib is built as well? I know makefiles but u-boot is quite high
  level usage.

Once we have it adjusted and running I will create a patch to
have it added to the official version.

Thanks

bye  Fabi