This mostly includes the PPC changes for 4.1, which this time cover
Book3S HV only (debugging aids, minor performance improvements and some
cleanups).  But there are also bug fixes and small cleanups for ARM,
x86 and s390.

The task_migration_notifier revert and real fix is still pending review,
but I'll send it as soon as possible after -rc1.
Merge tag 'kvm-arm-for-4.1-take2' of git:// into kvm-master

KVM/ARM changes for v4.1, take #2:

Rather small this time:

- a fix for a nasty bug with virtual IRQ injection
- a fix for irqfd