ARM: dts: add support for Odroid-N2

Import HardKernel Odroid-N2 DT from Linux 5.3-rc1, commit 5f9e832c1370
("Linus 5.3-rc1") based on an Amlogic G12B S922X SoC.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Mark Kettenis <kettenis@openbsd.org>