Accessing x2APIC MSRs in xAPIC mode should result in GP exception according
to SDM section 10.12.2. Adding support to ACRN to inject GP into guests for
the same reason.
Tracked-On: #1626
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Reviewed-by: Xu Anthony <anthony.xu@intel.com>