Merge tag 'kvm-s390-next-4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390 features, kvm_get_vcpu_by_id and stat

Several features for s390
1. ESCA support (up to 248 vCPUs)
2. KVM detection: we  can now detect if we support KVM (e.g. does KVM
   under KVM work?)

kvm_stat:
1. cleanup the exit path

kvm_get_vcpu_by_id:
1. Use kvm_get_vcpu_by_id where appropriate
2. Apply a heuristic to optimize for ID VCPU == No. VCPU