media: dt: bindings: media: Document data lane numbering without lane reordering

Most devices do not support lane reordering and in many cases the
documentation of the data-lanes property is incomplete for such devices.
Document that in case the lane reordering isn't supported, monotonically
incremented values from 0 or 1 shall be used.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>