The V4L2SubdeviceFormatInfo structure, internal to the
v4l2_subdevice.cpp compilation unit, contains information about media
bus formats that will be useful in other parts of libcamera. To prepare
for this, expose the structure in the v4l2_subdevice.h header and turn
it into a class with a similar design as PixelFormatInfo.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>