drm/msm/dpu: Adjust CDM_MUX to support CWB PINGPONG

Similar to WB_MUX, CDM_MUX also needs to be adjusted to support
dedicated CWB PINGPONGs

Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/641272/
Link: https://lore.kernel.org/r/20250305-cdm-cwb-mux-fix-v1-1-16148ca6e4d2@quicinc.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>