drm/panel: himax-hx8394: Drop prepare/unprepare tracking

Drop the panel specific prepare/unprepare logic. This is now tracked
by the DRM stack [1].

[1] commit d2aacaf0 ("drm/panel: Check for already prepared/enabled in
drm_panel")
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20231204185719.569021-2-macroalpha82@gmail.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204185719.569021-2-macroalpha82@gmail.com

drivers/gpu/drm/panel/panel-himax-hx8394.c

@@ -68,7 +68,6 @@ struct hx8394 {
 	struct gpio_desc *reset_gpio;
 	struct regulator *vcc;
 	struct regulator *iovcc;
-	bool prepared;
 
 	const struct hx8394_panel_desc *desc;
 };
@@ -262,16 +261,11 @@ static int hx8394_unprepare(struct drm_panel *panel)
 {
 	struct hx8394 *ctx = panel_to_hx8394(panel);
 
-	if (!ctx->prepared)
-		return 0;
-
 	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
 
 	regulator_disable(ctx->iovcc);
 	regulator_disable(ctx->vcc);
 
-	ctx->prepared = false;
-
 	return 0;
 }
 
@@ -280,9 +274,6 @@ static int hx8394_prepare(struct drm_panel *panel)
 	struct hx8394 *ctx = panel_to_hx8394(panel);
 	int ret;
 
-	if (ctx->prepared)
-		return 0;
-
 	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
 
 	ret = regulator_enable(ctx->vcc);
@@ -301,8 +292,6 @@ static int hx8394_prepare(struct drm_panel *panel)
 
 	msleep(180);
 
-	ctx->prepared = true;
-
 	return 0;
 
 disable_vcc: