ACPI video: Don't start video device until its associated input device has been allocated

Quoth Dmitry Torokhov:
In addition to bus notifier we do install device notifier explicitly
so it might fire up early. The easiest fox would be to move
acpi_video_bus_start_devices() after input_allocate_device() but
before input_register_device() - unregistered input devices can handle
input_event() calls just fine.

May fix crashes reported in:
https://bugzilla.kernel.org/show_bug.cgi?id=40672



Signed-off-by: Igor Murzov <e-mail@date.by>
Signed-off-by: Len Brown <len.brown@intel.com>