dt-bindings: arm: Convert Rockchip board/soc bindings to json-schema

Convert Rockchip SoC bindings to DT schema format using json-schema.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>
[move to per-board entries after confirming with Rob
 and added recently added boards]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Olof Johansson <olof@lixom.net>