regulator: lp872x: replacing legacy gpio interface for gpiod

Removing all linux/gpio.h and linux/of_gpio.h dependencies and replacing
them with the gpiod interface

Signed-off-by: Maíra Canal <maira.canal@usp.br>
Message-Id: <YWma2yTyuwS5XwhY@fedora>
Signed-off-by: Mark Brown <broonie@kernel.org>