dt-bindings: arm-smmu: Document SM8650 GPU SMMU

Document the GPU SMMU found on the SM8650 platform.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240216-topic-sm8650-gpu-v3-3-eb1f4b86d8d3@linaro.org


Signed-off-by: Will Deacon <will@kernel.org>