drm/bridge: rcar: Drop unused variables due to drm_of_get_data_lanes_count_ep

The rcar_mipi_dsi_parse_dt() now contains two uninitialized variables
due to conversion to common drm_of_get_data_lanes_count_ep() helper.
Drop them.

Fixes: d643daaf ("drm/bridge: rcar: Convert to drm_of_get_data_lanes_count_ep")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220612132152.91052-3-marex@denx.de