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>

Documentation/devicetree/bindings/media/video-interfaces.txt

@@ -108,7 +108,10 @@ Optional endpoint properties
   determines the logical lane number, while the value of an entry indicates
   physical lane, e.g. for 2-lane MIPI CSI-2 bus we could have
   "data-lanes = <1 2>;", assuming the clock lane is on hardware lane 0.
-  This property is valid for serial busses only (e.g. MIPI CSI-2).
+  If the hardware does not support lane reordering, monotonically
+  incremented values shall be used from 0 or 1 onwards, depending on
+  whether or not there is also a clock lane. This property is valid for
+  serial busses only (e.g. MIPI CSI-2).
 - clock-lanes: an array of physical clock lane indexes. Position of an entry
   determines the logical lane number, while the value of an entry indicates
   physical lane, e.g. for a MIPI CSI-2 bus we could have "clock-lanes = <0>;",