power: supply: gpio-charger: Convert to GPIO descriptors

This converts the GPIO charger to use exclusively GPIO
descriptors, moving the two remaining platforms passing
global GPIO numbers over to using a GPIO descriptor table.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>