Unfortunately the HIOR setting code slipped into upstream QEMU
before it was pulled into upstream KVM. And since Murphy is always
right, comments on the patches only emerged on the pull request
leading to changes in the interface.

So here's an update to the HIOR setting. While at it, I also relaxed
it a bit since for HV KVM we can already run fine without and 3.2
works just fine with HV KVM but when not setting HIOR. We will only
need this when running PAPR in PR KVM.

Since we accidently changed the ABI and API along the way, we have
to update the underlying kernel headers together with the code that
uses it to not break bisectability.

Signed-off-by: Alexander Graf <agraf@suse.de>