eeepc-laptop: Add support for extended hotkeys

Newer Eees have extra hotkeys above the function keys. This patch adds support
for sending them through the input layer.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>