ARM: dts: sun8i: Add dts file for the NanoPi NEO SBC

The NanoPi NEO is a minimal H3 based SBC. It comes with 256/512M RAM, a
micro SD slot, 10/100Mbit ethernet and a single USB-A port.

Signed-off-by: James Pettigrew <james@innovum.com.au>
Reviewed-by: Rask Ingemann Lambertsen <ccc94453@vip.cybercity.dk>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>