Add support for MIPI DSI Host controller. Since MIPI DSI is not
available on stm32f746, the patch adds the "stm32f769.dtsi" file
containing the dsi node inside.
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>