drm/bridge/synopsys: dsi :remove is_panel_bridge

When using drm_of_panel_bridge_remove() we can simplify the
code and remove is_panel_bridge from dw_mipi_dsi structure.

Signed-off-by: Benjamin Gaignard <[e-mail]>
Reviewed-by: Philippe Cornu <[e-mail]>
Tested-by: Philippe Cornu <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

···
 	struct drm_bridge bridge;
 	struct mipi_dsi_host dsi_host;
 	struct drm_bridge *panel_bridge;
-	bool is_panel_bridge;
 	struct device *dev;
 	void __iomem *base;
 
···
 		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
-		dsi->is_panel_bridge = true;
 	}
 
 	dsi->panel_bridge = bridge;
···
 {
 	struct dw_mipi_dsi *dsi = host_to_dsi(host);
 
-	if (dsi->is_panel_bridge)
-		drm_panel_bridge_remove(dsi->panel_bridge);
+	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
 
 	drm_bridge_remove(&dsi->bridge);