leds: simatic-ipc-leds-gpio: Move two extra gpio pins into another table

There are two special pins needed to init the LEDs. We used to have them
at the end of the gpiod_lookup table to give to "leds-gpio". A cleaner
way is to have a dedicated table for the special pins.

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/20230524124628.32295-3-henning.schild@siemens.com