media: dt-bindings: media: rcar-vin: Align Gen2 and Gen3

Align description of the Gen2 and Gen3 bindings for parallel input.
This commit prepares for description of optional endpoint properties in ports
subnodes accepting parallel video connections.
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/rcar_vin.txt

@@ -39,9 +39,11 @@ Additionally, an alias named vinX will need to be created to specify
 which video input device this is.
 
 The per-board settings Gen2 platforms:
- - port sub-node describing a single endpoint connected to the vin
-   as described in video-interfaces.txt[1]. Only the first one will
-   be considered as each vin interface has one input port.
+
+- port - sub-node describing a single endpoint connected to the VIN
+  from external SoC pins as described in video-interfaces.txt[1].
+  Only the first one will be considered as each vin interface has one
+  input port.
 
 The per-board settings Gen3 platforms:
 
@@ -52,7 +54,7 @@ from local SoC CSI-2 receivers (port@1) depending on SoC.
 - renesas,id - ID number of the VIN, VINx in the documentation.
 - ports
     - port@0 - sub-node describing a single endpoint connected to the VIN
-      from external SoC pins described in video-interfaces.txt[1].
+      from external SoC pins as described in video-interfaces.txt[1].
       Describing more than one endpoint in port@0 is invalid. Only VIN
       instances that are connected to external pins should have port@0.
     - port@1 - sub-nodes describing one or more endpoints connected to