hv: vpci: handle the quirk part for pass through pci device cfg access in dm

There're some PCI devices need special handler for vendor-specical feature or
capability CFG access. The Intel GPU is one of them. In order to keep the ACRN-HV
clean, we want to throw the qurik part of PCI CFG asccess to DM to handle.

To achieve this, we implement per-device policy base on whether it needs quirk handler
for a VM: each device could configure as "quirk pass through device" or not. For a
"quirk pass through device", we will handle the general part in HV and the quirk part
in DM. For a non "quirk pass through device",  we will handle all the part in HV.

Tracked-On: #4371
Signed-off-by: Li Fei1 <fei1.li@intel.com>

hypervisor/include/dm/vpci.h

@@ -104,6 +104,8 @@ struct pci_vdev {
 
 	union pci_cfgdata cfgdata;
 
+	uint32_t flags;
+
 	/* The bar info of the virtual PCI device. */
 	uint32_t nr_bars; /* 6 for normal device, 2 for bridge, 1 for cardbus */
 	struct pci_vbar vbars[PCI_BAR_COUNT];