drm/msm/dpu: add CWB support to dpu_hw_wb

Adjust the WB_MUX configuration to account for using dedicated CWB
pingpong blocks.

Signed-off-by: Esha Bharadwaj <quic_ebharadw@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/629248/
Link: https://lore.kernel.org/r/20241216-concurrent-wb-v4-13-fe220297a7f0@quicinc.com