drm/panel: ltk050h3146w: add support for Leadtek LTK050H3148W-CTA6 variant

drm/panel: ltk050h3146w: add support for Leadtek LTK050H3148W-CTA6 variant

The LTK050H3148W-CTA6 is a 5.0" 720x1280 DSI display, whose driving
controller is a Himax HX8394-F, slightly different from LTK050H3146W by
its init sequence, mode details and mode flags.

Cc: Quentin Schulz <foss+kernel@0leil.net>
Signed-off-by: Klaus Goger <klaus.goger@theobroma-systems.com>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220131164723.714836-2-quentin.schulz@theobroma-systems.com