drm: panel: add TDO tl070wsh30 panel driver

This adds support for the TDO TL070WSH30 TFT-LCD panel module.
The panel has a 1024×600 resolution and uses 24 bit RGB per pixel.
It provides a MIPI DSI interface to the host, a built-in LED backlight
and touch controller.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915121912.4347-5-narmstrong@baylibre.com