media: uvcvideo: Add a metadata device node

Some UVC video cameras contain metadata in their payload headers. This
patch extracts that data, adding more clock synchronisation information,
on both bulk and isochronous endpoints and makes it available to the user
space on a separate video node, using the V4L2_CAP_META_CAPTURE capability
and the V4L2_BUF_TYPE_META_CAPTURE buffer queue type. By default, only the
V4L2_META_FMT_UVC pixel format is available from those nodes. However,
cameras can be added to the device ID table to additionally specify their
own metadata format, in which case that format will also become available
from the metadata node.

[Use put_unaligned instead of __put_unaligned_cpu64]
[Use put_unaligned for the sof field as well]

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>