ST7701 designed for small and medium sizes of TFT LCD display, is
capable of supporting up to 480RGBX864 in resolution. It provides
several system interfaces like MIPI/RGB/SPI.

Currently added support for Techstar TS8550B which is ST7701 based
480x854, 2-lane MIPI DSI LCD panel.

Driver now registering mipi_dsi device, but indeed it can extendable
for RGB if any requirement trigger in future.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190124215131.17452-2-jagan@amarulasolutions.com