drm/msm/dpu: inline dpu_plane_get_ctl_flush

There is no need to keep a separate function for calling into the ctl if
we already know all the details. Inline this function in the dpu_crtc.c

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/473152/
Link: https://lore.kernel.org/r/20220209172520.3719906-7-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>