pwm: atmel-tcb: Fix resource freeing in error path and remove

Several resources were not freed in the error path and the remove
function. Add the forgotten items.

Fixes: 34cbcd72 ("pwm: atmel-tcb: Add sama5d2 support")
Fixes: 061f8572

 ("pwm: atmel-tcb: Switch to new binding")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>