If split-lm is used (for ex, on sdm845), we can have multiple ping-
pongs, but only a single phys encoder.  We need to configure dithering
on each of them.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Tested-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Kalyan Thota <kalyan_t@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>