This isn't quite fully baked yet, and I should probably split it out further.
- Change relocatable kernel related #ifdefs to be RELOCATABLE_KERNEL instead of powerpc, to allow for other platforms to use relocatable kernels in the future.
- Add powerpc64 ifunc bits.
- Add a trick to relocate to the DMAP even on virtual mode OpenFirmware.
- Remove DB_STOFFS hack so we start getting a real picture of what's going on with memory addresses on PPC64.
- Fix symbol relocation to work as intended by relocating the symbol table values. (XXX need to check if there's a more straightforward way to process this.)
- Add a trick to allow self-loading symbol tables on powernv by setting the initrd to load the kernel binary.