sony-laptop: Make the driver use MSC_SCAN and a setkeycode and getkeycode key table.

The following is the only way I could think of to hide some events as
per Dmitry suggestions while still using the default {set,get}keycode
implementation.

Make the driver use MSC_SCAN and a setkeycode and getkeycode key table.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Richard Hughes <richard@hughsie.com>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>