vfio/igd: Introduce x-igd-lpc option for LPC bridge ID quirk

vfio/igd: Introduce x-igd-lpc option for LPC bridge ID quirk

The LPC bridge/Host bridge IDs quirk is also not dependent on legacy
mode. Recent Windows driver no longer depends on these IDs, as well as
Linux i915 driver, while UEFI GOP seems still needs them. Make it an
option to allow users enabling and disabling it as needed.

Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Corvin Köhne <c.koehne@beckhoff.com>
Link: https://lore.kernel.org/qemu-devel/20250306180131.32970-10-tomitamoeko@gmail.com
[ clg: - Fixed spelling in vfio_probe_igd_config_quirk() ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>