drm/panel: sony-acx565akm: Fix SPI alias

The panel-sony-acx565akm 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: 1c8fc3f0

 ("drm/panel: Add driver for the Sony ACX565AKM 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/20191007170801.27647-4-laurent.pinchart@ideasonboard.com
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>