In current code, wait_pcpus_offline() and make_pcpu_offline() are called by
both shutdown_vm() and reset_vm(), but this is not needed when lapic_pt is
not enabled for the vcpus of the VM.
The patch merged offline pcpus part code into a common
offline_lapic_pt_enabled_pcpus() api for shutdown_vm() and reset_vm() use and
called only when lapic_pt is enabled.
Tracked-On: #4325
Signed-off-by: Victor Sun <victor.sun@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>