drm/panel: sharp-ls043t1le01: Stop tracking prepared

As talked about in commit d2aacaf07395 ("drm/panel: Check for already
prepared/enabled in drm_panel"), we want to remove needless code from
panel drivers that was storing and double-checking the
prepared/enabled state. Even if someone was relying on the
double-check before, that double-check is now in the core and not
needed in individual drivers.

Cc: Werner Johansson <[e-mail]>
Cc: Dmitry Baryshkov <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Acked-by: Maxime Ripard <[e-mail]>
Signed-off-by: Douglas Anderson <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
Link: https://lore.kernel.org/r/20240604172305.v3.19.I56849dbe7c906f0cff076dc5286fd05c7e3e9c18@changeid
Signed-off-by: Neil Armstrong <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/20240604172305.v3.19.I56849dbe7c906f0cff076dc5286fd05c7e3e9c18@changeid

drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c

···
 
 	struct regulator *supply;
 	struct gpio_desc *reset_gpio;
-
-	bool prepared;
 };
 
 static inline struct sharp_nt_panel *to_sharp_nt_panel(struct drm_panel *panel)
···
 	struct sharp_nt_panel *sharp_nt = to_sharp_nt_panel(panel);
 	int ret;
 
-	if (!sharp_nt->prepared)
-		return 0;
-
 	ret = sharp_nt_panel_off(sharp_nt);
 	if (ret < 0) {
 		dev_err(panel->dev, "failed to set panel off: %d\n", ret);
···
 	if (sharp_nt->reset_gpio)
 		gpiod_set_value(sharp_nt->reset_gpio, 0);
 
-	sharp_nt->prepared = false;
-
 	return 0;
 }
 
···
 {
 	struct sharp_nt_panel *sharp_nt = to_sharp_nt_panel(panel);
 	int ret;
-
-	if (sharp_nt->prepared)
-		return 0;
 
 	ret = regulator_enable(sharp_nt->supply);
 	if (ret < 0)
···
 		dev_err(panel->dev, "failed to set panel on: %d\n", ret);
 		goto poweroff;
 	}
-
-	sharp_nt->prepared = true;
 
 	return 0;