Right now sregs is unused on PPC, so we can use it for initialization
of the CPU.

KVM on BookE always virtualizes the host CPU. On Book3s we go a step further
and take the PVR from userspace that tells us what kind of CPU we are supposed
to virtualize, because we support Book3s_32 and Book3s_64 guests.

In order to get that information, we use the sregs ioctl, because we don't
want to reset the guest CPU on every normal register set.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>