dt-bindings: clock: add QCOM SM6125 display clock bindings

Add device tree bindings for display clock controller for
Qualcomm Technology Inc's SM6125 SoC.

Signed-off-by: Martin Botka <martin.botka@somainline.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220303131812.302302-3-marijn.suijten@somainline.org