drm/bridge: tc358767: Fix DP bridge mode detection from DT endpoints

Per toshiba,tc358767.yaml DT binding document, port@2 the output (e)DP
port is optional. In case this port is not described in DT, the bridge
driver operates in DPI-to-DP mode. Make sure the driver treats this as
a valid mode of operation instead of reporting invalid mode.

Fixes: 71f7d9c0 ("drm/bridge: tc358767: Detect bridge mode from connected endpoints in DT")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429204625.241591-1-marex@denx.de

drivers/gpu/drm/bridge/tc358767.c

@@ -1964,7 +1964,9 @@ static int tc_probe_bridge_endpoint(struct tc_data *tc)
 	struct of_endpoint endpoint;
 	struct device_node *node = NULL;
 	const u8 mode_dpi_to_edp = BIT(1) | BIT(2);
+	const u8 mode_dpi_to_dp = BIT(1);
 	const u8 mode_dsi_to_edp = BIT(0) | BIT(2);
+	const u8 mode_dsi_to_dp = BIT(0);
 	const u8 mode_dsi_to_dpi = BIT(0) | BIT(1);
 	u8 mode = 0;
 
@@ -1990,11 +1992,11 @@ static int tc_probe_bridge_endpoint(struct tc_data *tc)
 		mode |= BIT(endpoint.port);
 	}
 
-	if (mode == mode_dpi_to_edp)
+	if (mode == mode_dpi_to_edp || mode == mode_dpi_to_dp)
 		return tc_probe_edp_bridge_endpoint(tc);
 	else if (mode == mode_dsi_to_dpi)
 		return tc_probe_dpi_bridge_endpoint(tc);
-	else if (mode == mode_dsi_to_edp)
+	else if (mode == mode_dsi_to_edp || mode == mode_dsi_to_dp)
 		dev_warn(dev, "The mode DSI-to-(e)DP is not supported!\n");
 	else
 		dev_warn(dev, "Invalid mode (0x%x) is not supported!\n", mode);