[Skiboot] opal-prd Makefile hacks

[Stewart Smith]

Jeremy Kerr <jk at ozlabs.org> writes:
>>  - 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?

I have no objections. I also have no objections for building the
non-userspace bits too :)