Document dt-bindings for Rockchip RV1126 clock controller.

Cc: linux-clk@vger.kernel.org
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Link: https://lore.kernel.org/r/20220915163947.1922183-4-jagan@edgeble.aiSigned-off-by: Heiko Stuebner <heiko@sntech.de>