Move x86 KVM ioctls under #ifdef X86
Add compat definitions for recent powerpc KVM features
Sanitise F_SETSIG argument to avoid SIGINT

It's possible to send ourselves a SIGINT using F_SETSIG. This is then
interpreted as a Ctrl-c from the user and trinity quits.

Avoid SIGINT, instead use 0, which switches back to the default
behaviour of sending SIGIO.
Removing arguments of KVM_S390_STORE_STATUS

Removing unused arguments of KVM_S390_STORE_STATUS.