Get the privacy-screen / lcdshadow ACPI handles once and cache them,
instead of retrieving them every time we need them.
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NMark Pearson <markpearson@lenovo.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211005202322.700909-8-hdegoede@redhat.com