leds: simatic-ipc-leds-gpio: Introduce more Kconfig switches

To describe the dependency chain better and allow for potential
fine-grained config tuning, introduce Kconfig switch for the individual
GPIO based drivers.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230524124628.32295-5-henning.schild@siemens.com