arm: dts: owl-s500: Add Sparky

Add a Device Tree for the Allo.com Sparky SBC.

Acked-by: Sudeep Kumar <sudeepkumar@cem-solutions.net>
[AF: Adjusted SPDX-License-Identifier style]
Signed-off-by: Andreas Färber <afaerber@suse.de>