drm/panel: khadas-ts050: Don't call unprepare+disable at shutdown/remove

It's the responsibility of a correctly written DRM modeset driver to
call drm_atomic_helper_shutdown() at shutdown time and that should be
disabling / unpreparing the panel if needed. Panel drivers shouldn't
be calling these functions themselves.

A recent effort was made to fix as many DRM modeset drivers as
possible [1] [2] [3] and most drivers are fixed now.

Unfortunately, grepping mainline for this panel's compatible string
shows no hits, so we can't be 100% sure if the DRM modeset driver used
with this panel has been fixed. If it is found that the DRM modeset
driver hasn't been fixed then this patch could be temporarily reverted
until it is.

[1] https://lore.kernel.org/r/20230901234015.566018-1-dianders@chromium.org
[2] https://lore.kernel.org/r/20230901234202.566951-1-dianders@chromium.org
[3] https://lore.kernel.org/r/20230921192749.1542462-1-dianders@chromium.org

Cc: Jacobe Zang <jacobe.zang@wesion.com>
Cc: Nicolas Belin <nbelin@baylibre.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240604172305.v3.4.I1ee65e7905bf5bf46a0e6c5126ac3c7aa25cb80b@changeidSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240604172305.v3.4.I1ee65e7905bf5bf46a0e6c5126ac3c7aa25cb80b@changeid

drivers/gpu/drm/panel/panel-khadas-ts050.c

@@ -880,16 +880,6 @@ static void khadas_ts050_panel_remove(struct mipi_dsi_device *dsi)
 		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);
 
 	drm_panel_remove(&khadas_ts050->base);
-	drm_panel_disable(&khadas_ts050->base);
-	drm_panel_unprepare(&khadas_ts050->base);
-}
-
-static void khadas_ts050_panel_shutdown(struct mipi_dsi_device *dsi)
-{
-	struct khadas_ts050_panel *khadas_ts050 = mipi_dsi_get_drvdata(dsi);
-
-	drm_panel_disable(&khadas_ts050->base);
-	drm_panel_unprepare(&khadas_ts050->base);
 }
 
 static struct mipi_dsi_driver khadas_ts050_panel_driver = {
@@ -899,7 +889,6 @@ static struct mipi_dsi_driver khadas_ts050_panel_driver = {
 	},
 	.probe = khadas_ts050_panel_probe,
 	.remove = khadas_ts050_panel_remove,
-	.shutdown = khadas_ts050_panel_shutdown,
 };
 module_mipi_dsi_driver(khadas_ts050_panel_driver);