Video subdevices, like cameras, decoders, connect to video bridges over
specialised busses. Data is being transferred over these busses in various
formats, which only loosely correspond to fourcc codes, describing how video
data is stored in RAM. This is not a one-to-one correspondence, therefore we
cannot use fourcc codes to configure subdevice output data formats. This patch
adds codes for several such on-the-bus formats and an API, similar to the
familiar .s_fmt(), .g_fmt(), .try_fmt(), .enum_fmt() API for configuring those
codes. After all users of the old API in struct v4l2_subdev_video_ops are
converted, it will be removed. Also add helper routines to support generic
pass-through mode for the soc-camera framework.

 create mode 100644 drivers/media/video/soc_mediabus.c
 create mode 100644 include/media/soc_mediabus.h
 create mode 100644 include/media/v4l2-mediabus.h
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>