media: dt-bindings: qcom,sm8250-venus: sort out power domains

media: dt-bindings: qcom,sm8250-venus: sort out power domains

First of all, on SM8250 Iris (ex-Venus) core needs to scale clocks which
are powered by the MMCX domain. Add MMCX domain to the list of the power
domain to be used on this platform.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>
Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>