Because we depend on guest OS to switch x2apic mode to enable lapic pass-thru, vlapic is working at the early stage of booting, eg: in virtual boot loader.
After lapic pass-thru enabled, no interrupt should be injected via vlapic any more.
This commit resets the vlapic to clear the pending status and adds ptapic_ops to enforce that no more interrupt accepted/injected via vlapic.
Tracked-On: #3227
Signed-off-by: Yan, Like <like.yan@intel.com>