pwm: renesas-tpu: remove unused struct tpu_pwm_platform_data

The struct is not used anymore and the polarity initialization will be
done using the PWM lookup table (or device tree).

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>