Current kvm wallclock does not consider the total_sleep_time which could cause
wrong wallclock in guest after host suspend/resume. This patch solve
this issue by counting total_sleep_time to get the correct host boot time.

Cc: stable@kernel.org
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NGlauber Costa <glommer@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>