Fix some typos and while at it also use "PS" as the name for the central
"HOME" button on Sony controllers, this is how Sony itself calls it.
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NAntonio Ospite <ospite@studenti.unina.it>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>