dt-bindings: display: Document Himax HX8394 panel rotation

Document panel rotation for Himax HX8394 display panel.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231204185719.569021-4-macroalpha82@gmail.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204185719.569021-4-macroalpha82@gmail.com