OvmfPkg/VirtioMmioDeviceLib: virtio 1.0: Add default QueueNum

Use QueueNumMax as QueueNum default for drivers which do not
explicitly call VIRTIO_DEVICE_PROTOCOL->SetQueueSize().

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDevice.h

@@ -30,6 +30,7 @@
 typedef struct {
   UINT32                 Signature;
   UINT32                 Version;
+  UINT16                 QueueNum;
   VIRTIO_DEVICE_PROTOCOL VirtioDevice;
   PHYSICAL_ADDRESS       BaseAddress;
 } VIRTIO_MMIO_DEVICE;