Initialize IA32_FEATURE_CONTROL MSR in reset and migration

The recent KVM patch adds IA32_FEATURE_CONTROL support. QEMU needs
to clear this MSR when reset vCPU and keep the value of it when
migration. This patch add this feature.

Signed-off-by: Arthur Chunqi Li <yzt356@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
