drm/panel: tpo-td043mtea1: Fix SPI alias

The panel-tpo-td043mtea1 driver incorrectly includes the OF vendor
prefix in its SPI alias. Fix it, and move the manual alias to an SPI
module device table.

Fixes: dc2e1e5b

 ("drm/panel: Add driver for the Toppoly TD043MTEA1 panel")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191007170801.27647-6-laurent.pinchart@ideasonboard.com
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>