KVM: s390: Fixes and features for 4.11 (via kvm/next)
- enable some simd extensions for guests
- enable nx for guests
- debug log for cpu model
- PER fixes
- remove bitwise annotation from ar_t
- detect guests in operation exception program check loops
- fix potential null-pointer dereference for ucontrol guests
- also contains merge for fix that went into 4.10 to avoid conflicts