KVM: PPC: Implement kvmppc_xlate for all targets

We have a nice API to find the translated GPAs of a GVA including protection
flags. So far we only use it on Book3S, but there's no reason the same shouldn't
be used on BookE as well.

Implement a kvmppc_xlate() version for BookE and clean it up to make it more
readable in general.

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

diff --cc arch/powerpc/include/asm/kvm_ppc.h
Simple merge

diff --cc arch/powerpc/kvm/book3s.c
Simple merge

diff --cc arch/powerpc/kvm/booke.c
Simple merge