dt-bindings: clock: Add SDX55 GCC clock bindings

Add device tree bindings for global clock controller on SDX55 SoCs.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201126072844.35370-2-manivannan.sadhasivam@linaro.org


Signed-off-by: Stephen Boyd <sboyd@kernel.org>