topstar-laptop: add new driver for hotkeys support on Topstar N01

This adds Topstar Laptop Extras ACPI driver. It enables hotkeys
functionality with Topstar N01 netbook. Besides hotkeys there are
other functions exposed by its ACPI firmware, but for now only
hotkeys reporting on Topstar N01 is supported. Topstar is a chinese
manufacturer, its website can be currently reached at
http://www.topstardigital.cn/



Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Reviewed-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Reviewed-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>