pci-ids: document modern virtio-pci ids in pci.h too

While being at it add a #define for the magic 0x1040 number.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20221004112100.301935-6-kraxel@redhat.com>