Input: soc_button_array - update calls to gpiod_get*()

Add the new flags argument to calls of (devm_)gpiod_get*().

Currently both forms (with or without the flags argument) are valid thanks
to transitional macros in <linux/gpio/consumer.h>. These macros will be
removed once all consumers are updated and the flags argument will become
compulsory.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>