drm/msm/dp: remove dp_display_en/disable prototypes and data argument

Remove unused dp_display_en/disable prototypes. While we are at it,
remove extra 'data' argument that is unused.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/490104/
Link: https://lore.kernel.org/r/20220617232434.1139950-3-dmitry.baryshkov@linaro.org


Signed-off-by: Rob Clark <robdclark@chromium.org>