Merge branch 's390-for-upstream' of git://repo.or.cz/qemu/agraf

* 's390-for-upstream' of git://repo.or.cz/qemu/agraf:
  s390: sclp ascii console support
  s390: sclp signal quiesce support
  s390: sclp event support
  s390: sclp base support
  s390: use sync regs for register transfer
  s390/kvm_stat: correct sys_perf_event_open syscall number
  s390x: fix -initrd in virtio machine