Input: xpad - fix for "Mad Catz Street Fighter IV FightPad" controllers

Added MAP_TRIGGERS_TO_BUTTONS for Mad Catz Street Fighter IV FightPad
device. This controller model was already supported by the xpad
driver, but none of the buttons work correctly without this change.

Tested on kernel version 3.9.5.

Signed-off-by: Shawn Joseph <jms.576@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>