dt-bindings: clock: exynos850: Add Exynos850 CMU_MFCMSCL

CMU_MFCMSCL generates MFC, M2M, MCSC and JPEG clocks for BLK_MFCMSCL.
Add clock indices and binding documentation for CMU_MFCMSCL.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220809113323.29965-4-semen.protsenko@linaro.org