drm/panel: sharp-ls043t1le01: drop dummy functions and data fields

Drop sharp_nt_panel_disable() and sharp_nt_panel_enable(), which bear no
useful code. Also drop sharp_nt_panel::enable and sharp_nt_panel::mode
fields which also provide no use now.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230507172639.2320934-2-dmitry.baryshkov@linaro.org