Add keymap for Sony Playstation Dualshock 4 Controller.

Add keymap for Sony Playstation Dualshock 4 Controller.

cat /proc/bus/input/devices shows it as "Sony Computer Entertainment Wireless Controller"
This conflicts with the PS3 controller as it is named the same thing.

It is also show as "Wireless Controller" in OpenELEC

I am not quite sure what to do about this as the PS3 controller is labelled the same thing (or so I believe, I don't have a controller to test). So I have removed the duplicate name from the PS3 controller keymap for now.

I don't know if there is another way to detect names or not but I thought I would just PR this to see what others have to say.