Modify license to include dual licensing as GPL-2.0-only OR MIT
license for device trees belonging to BeagleBoard.org Foundation
platforms. This allows for Linux kernel device tree to be used in
other Operating System ecosystems such as Zephyr or FreeBSD.

While at this, update the GPL-2.0 to be GPL-2.0-only to be in sync
with latest SPDX conventions (GPL-2.0 is deprecated).

While at this, update the copyright year to sync with current year
to indicate license change.

Cc: Ayush Singh <ayushdevel1325@gmail.com>
Cc: Jason Kridner <jkridner@beagleboard.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Robert Nelson <robertcnelson@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Wadim Egorov <w.egorov@phytec.de>
Acked-by: Ayush Singh <ayushdevel1325@gmail.com>
Acked-by: Jason Kridner <jkridner@beagleboard.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Robert Nelson <robertcnelson@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Wadim Egorov <w.egorov@phytec.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240122145539.194512-14-nm@ti.comSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>