dt-bindings: edac: Dmc-520.yaml

Add the device tree bindings for the EDAC driver dmc520_edac.

Signed-off-by: Lei Wang <leiwang_git@outlook.com>
Signed-off-by: Shiping Ji <shiping.linux@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lkml.kernel.org/r/5354a9c3-5b5a-486a-9d19-fa9be169faef@gmail.com