vfio/igd: add Gemini Lake and Comet Lake device ids

Both Gemini Lake and Comet Lake are gen 9 devices. Many user reports
on internet shows legacy mode of igd passthrough works as qemu treats
them as gen 8 devices by default before e433f20897 ("vfio/igd:
return an invalid generation for unknown devices").

Reviewed-by: Corvin Köhne <c.koehne@beckhoff.com>
Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20241206122749.9893-6-tomitamoeko@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/igd.c

@@ -81,8 +81,10 @@ static int igd_gen(VFIOPCIDevice *vdev)
     case 0x2200:    /* Cherryview */
         return 8;
     case 0x1900:    /* Skylake */
+    case 0x3100:    /* Gemini Lake */
     case 0x5900:    /* Kaby Lake */
     case 0x3e00:    /* Coffee Lake */
+    case 0x9B00:    /* Comet Lake */
         return 9;
     case 0x4500:    /* Elkhart Lake */
         return 11;