dt-bindings: clock: Add SM8550 GCC clocks

Add device tree bindings for global clock controller on SM8550 SoCs.

Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221130112852.2977816-2-abel.vesa@linaro.org