kvm: x86: add mce support

Port qemu-kvm's MCE support

commit c68b2374c9048812f488e00ffb95db66c0bc07a7
Author: Huang Ying <ying.huang@intel.com>
Date:   Mon Jul 20 10:00:53 2009 +0800

    Add MCE simulation support to qemu/kvm

    KVM ioctls are used to initialize MCE simulation and inject MCE. The
    real MCE simulation is implemented in Linux kernel. The Kernel part
    has been merged.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
