drm/msm/dsi: remove duplicate fields from dsi_pll_Nnm instances

Drop duplicate fields pdev and id from dsi_pll_Nnm instances. Reuse
those fields from the provided msm_dsi_phy.

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/20210331105735.3690009-22-dmitry.baryshkov@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>