gpiolib: Remove data-less gpiochip_add() function

gpiolib: Remove data-less gpiochip_add() function

GPIO chips should be added with driver-private data associated with the
chip. If none is needed, NULL can be used. All users already do this
except one, fix that here. With no more users of the base gpiochip_add()
we can drop this function so no more users show up later.

Signed-off-by: Andrew Davis <afd@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240610135313.142571-1-afd@ti.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>