[Etherboot-developers] 5.1.4/5: more relocation fixes

[<ke...@us...>]

Checked in a bunch of possible fixes for relocation for natsemi, fa311,
and davicom drivers.

The lance based drivers look hard to fix because it has only a 24-bit
address register, it wasn't meant to do DMA above 16MB.

Guess I better ready a 5.1.5 release :-|.