[U-Boot] [PATCH] Add information about return values of xxx_eth_register() in documentation

[Ben Warren]

Mike,

Ben Warren wrote:
> As discussed on mailing list, <0 indicates failure, >=0 indicates number
> of interfaces found.
>
> Also added blurb about private data
>   
I'm going to go ahead and put this in the net repo.  If you don't like 
it, let me know and we'll back it out.

regards,
Ben