asus-laptop: handle keyboard backlight keys

Add support for the Fn+F3/Fn+F4 keys and map them
as KEY_KBDILLUMUP and KEY_KBDILLUMDOWN.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
1 file changed