[Skiboot] opal-prd Makefile hacks

[Jeremy Kerr]

Hi Ben,

>  - Linking to libflash was bad because we would build .o's in the
> original directory which conflict with skiboot own .o's (and typically
> have the wrong endian etc...). So instead I link individual .c/.h files
> into a local directory.
> 
>  - The KERNEL_DIR stuff is a trainwreck. Not your fault Jeremy,

Oh, it's totally my fault. This was just a temporary hack while we sort
out the official kernel headers. I'll sort them out into a proper
uapi-able include today.

Any objections to creating an Ubuntu package for the userspace bits of
skiboot?

Cheers,


Jeremy