Input: edt-ft5x06 - several cleanups; no functional change

- remove redundant parens
- remove redundant type casts
- fix mixed tab/space indentation

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>