arm: vexpress: Add a devicetree files for juno

arm: vexpress: Add a devicetree files for juno

Sync these file, obtained from Linux v5.15.

Add a note for the maintainer, and SPDX lines where they are missing.
The added lines are:

   SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause

Note, this matches the text in those files, but is not the same as the
GPL-2.0 of some files.

[1] https://releases.linaro.org/android/reference-lcr/juno/7.1-17.05/

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>