leds: simatic-ipc-leds-gpio: Fix comment style in SPDX header

This was found with giving the file to checkpatch.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
Link: https://lore.kernel.org/r/20230706161040.21152-3-henning.schild@siemens.com


Signed-off-by: Lee Jones <lee@kernel.org>