drm/bridge: tc358767: Fix (e)DP bridge endpoint parsing in dedicated function

drm/bridge: tc358767: Fix (e)DP bridge endpoint parsing in dedicated function

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. The drm_of_find_panel_or_bridge()
call in tc_probe_edp_bridge_endpoint() returns -ENODEV in case port@2
is not present in DT and this specific return value is incorrectly
propagated outside of tc_probe_edp_bridge_endpoint() function. All
other error values must be propagated and are propagated correctly.

Return 0 in case the port@2 is missing instead, that reinstates the
original behavior before the commit this patch fixes.

Fixes: 8478095a8c4b ("drm/bridge: tc358767: Move (e)DP bridge endpoint parsing into dedicated function")
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/20220428213132.447890-1-marex@denx.de