target-ppc: spapr: e500: fix to use cpu_dt_id

target-ppc: spapr: e500: fix to use cpu_dt_id

This makes use of @cpu_dt_id and related API in:
1. emulated XICS hypercall handlers as they receive fixed CPU indexes;
2. XICS-KVM to enable in-kernel XICS on right CPU;
3. device-tree renderer.

This removes @cpu_index fixup as @cpu_dt_id is used instead so QEMU monitor
can accept command-line CPU indexes again.

This changes kvm_arch_vcpu_id() to use ppc_get_vcpu_dt_id() as at the moment
KVM CPU id and device tree ID are calculated using the same algorithm.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Mike Day <ncmike@ncultra.org>
Signed-off-by: Alexander Graf <agraf@suse.de>