KVM: move code related to KVM_SET_BOOT_CPU_ID to x86

This is another remnant of ia64 support.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --cc arch/x86/include/asm/kvm_host.h
Simple merge

diff --cc arch/x86/kvm/x86.c
Simple merge

diff --cc include/linux/kvm_host.h
Simple merge

diff --cc virt/kvm/kvm_main.c
Simple merge