[ACPI] acpi_remove_notify_handler() on video driver unload

The video driver doesn't properly remove all the notify handlers
on module unload.  This has a side effect of subdevices failing
to register on module reload, but sudden death looms if the
handlers trigger after the module is unloaded.

Signed-off-by: Karol Kozimor <sziwan@hell.org.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>