drm/panel: boe-th101mb31ig002 : using drm_connector_helper_get_modes_fixed()

Use public functions( drm_connector_helper_get_modes_fixed()) to
get porch parameters.

Signed-off-by: Zhaoxiong Lv <[e-mail]>
Reviewed-by: Douglas Anderson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Neil Armstrong <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/panel/panel-boe-th101mb31ig002-28a.c

···
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_modes.h>
 #include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
 
 struct boe_th101mb31ig002;
 
···
 						      struct boe_th101mb31ig002,
 						      panel);
 	const struct drm_display_mode *desc_mode = ctx->desc->modes;
-	struct drm_display_mode *mode;
-
-	mode = drm_mode_duplicate(connector->dev, desc_mode);
-	if (!mode) {
-		dev_err(panel->dev, "Failed to add mode %ux%u@%u\n",
-			desc_mode->hdisplay, desc_mode->vdisplay,
-			drm_mode_vrefresh(desc_mode));
-		return -ENOMEM;
-	}
-
-	drm_mode_set_name(mode);
 
 	connector->display_info.bpc = 8;
-	connector->display_info.width_mm = mode->width_mm;
-	connector->display_info.height_mm = mode->height_mm;
-
 	/*
 	 * TODO: Remove once all drm drivers call
 	 * drm_connector_set_orientation_from_panel()
 	 */
 	drm_connector_set_panel_orientation(connector, ctx->orientation);
 
-	drm_mode_probed_add(connector, mode);
-
-	return 1;
+	return drm_connector_helper_get_modes_fixed(connector, desc_mode);
 }
 
 static enum drm_panel_orientation