[OE-core] Build for powerpc spe broken

[Eibach, Dirk]

Commits
12f0a0d3e1afe90633c8b95d36670ab0f156e912
785962440131f993b912d26cba39dc7ffc91aad4
01fd9be5db633d881c789c5b119f794a3f1000da

break building for powerpc spe, it seems a powerpc-nf toolchain is
built.

Patch "[PATCH 3/4] arch-powerpc.inc: use default value of TUNE_PKGARCH"
was not pulled and I don't see a replacement for it yet. Matthew, do you
have something in your queue?

Cheers
Dirk