clk: rockchip: Add dt-binding header for RV1126

Add the dt-bindings header for the Rockchip RV1126, that gets shared
between the clock controller and the clock references in the dts.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Link: https://lore.kernel.org/r/20220915163947.1922183-3-jagan@edgeble.ai
Signed-off-by: Heiko Stuebner <heiko@sntech.de>