eeepc-laptop: switch to using sparse keymap library

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>