gpio: pisosr: Use devm_gpiochip_add_data() to simplify remove path

Use devm version of gpiochip add function to handle removal for us.

While here update copyright and module author.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>