Add subclass for virtio-console pci device. Without the subclass, the
device may be probed by 8250_pci serial driver, and lead to segment
fault in acrn-dm. This issue appears when running debian as Guest OS.
But there is a potential issue, if a new serial driver, which use class
and subclass same as virtio-console, the problem may still trigger. Need
to fix it case by case.
Tracked-On: #3615
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Acked-by: Yin Fengwei <fengwei.yin@intel.com>
2d57c5feb7