arm64: dts: broadcom: Add reference to RPi 400

This adds a reference to the dts of the Raspberry Pi 400,
so we don't need to maintain the content in arm64.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Link: https://lore.kernel.org/r/1622981777-5023-8-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
2 files changed