gpio: mpc8xxx: Use 'devm_gpiochip_add_data()' to simplify the code and avoid a leak

[ Upstream commit 889a1b3f ]

If an error occurs after a 'gpiochip_add_data()' call it must be undone by
a corresponding 'gpiochip_remove()' as already done in the remove function.

To simplify the code a fix a leak in the error handling path of the probe,
use the managed version instead (i.e. 'devm_gpiochip_add_data()')

Fixes: 698b8eea ("gpio/mpc8xxx: change irq handler from chained to normal")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>