drm/msm/dsi: drop vco_delay setting from 7nm, 10nm, 14nm drivers

These drivers do not use vco_delay variable, so drop it from all of
them.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Tested-by: Stephen Boyd <swboyd@chromium.org> # on sc7180 lazor
Link: https://lore.kernel.org/r/20210331105735.3690009-15-dmitry.baryshkov@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>