pinctrl: samsung: Use devres version of gpiochip_add_data

Use devm_gpiochip_add_data to simplify the error path in
samsung_gpiolib_register.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>