This adds documentation for a new ILI9163 based, SPI connected display.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211015150131.1020878-2-daniel@zonque.org