dt-binding: leds: Publish common bindings under dual license

dt-binding: leds: Publish common bindings under dual license

Changes leds/common.h DT binding header file to be published under GPLv2
or BSD-2-Clause license terms. This change allows this common LED
bindings header file to be used in software components as bootloaders
and OSes that are not published under GPLv2 terms.

All contributors to leds/common.h file in copy.

Signed-off-by: Corvin Köhne <c.koehne@beckhoff.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Acked-by: Gergo Koteles <soyer@irl.hu>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://patch.msgid.link/20260408062942.7128-1-corvin.koehne@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>