dt-bindings: Add binding for Hardkernel Odroid Go Advance

Add a compatible for the Odroid Go Advance from Hardkernel.
The compatible used by the vendor already is odroid-go2, to distinguish
it from the previous (microcontroller-based) Odroid Go, so we're keeping
that, also to not cause unnecessary incompatibilites.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200414082938.2977572-2-heiko@sntech.de


Signed-off-by: Heiko Stuebner <heiko@sntech.de>