ACPI video hotkey: remove invalid events handler for video output devices

Both ACPI_VIDEO_NOTIFY_SWITCH and ACPI_VIDEO_NOTIFY_PROBE
are valid for video bus devices only. Actually ACPI video output
device should never be notified for a output device switch/probe.

ACPI bus devices notify handler already has the code to
handle these kinds of events.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>