MIPS: Octeon: Add DTS for D-Link DSR-500N.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14249/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>