dt-bindings: clock: Add SM8350 VIDEOCC

SM8350, like most recent higher-end chips has a separate clock
controller block just for the Venus IP. Document it.

The binding was separated as the driver, unlike the earlier ones, doesn't
expect clock-names to keep it easier to maintain.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230413-topic-lahaina_vidcc-v4-1-86c714a66a81@linaro.org