dt-bindings: media: add bindings for stm32 dcmipp

Add the yaml binding for the ST Microelectronics STM32 DCMIPP
(Digital Camera Memory Interface Pixel Processor)

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>