sony-laptop: Fix event reading in sony-laptop

The rewritten event reading code from sonypi was absolutely wrong,
this patche makes things functional for type2 and type1 models.

Cc: Andrei Paskevich <andrei@capet.iut-fbleau.fr>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>