sony-laptop: add Type4 model

Recent Vaio models (UX, SZ and presumably TZ and others) add more
events and a slightly different handling of Fn key events for
additional hotkeys (s1, s2, zoom-in/out, etc.).

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>