dt-bindings: mtd: nand-controller: Fix a comment in the examples

The controller properties should be in the controller 'parent' node,
while properties in the children nodes are specific to the NAND
*chip*. This error was already present during the yaml conversion.

Fixes: 2d472aba ("mtd: nand: document the NAND controller/NAND chip DT representation")
Signed-off-by: NMiquel Raynal <miquel.raynal@bootlin.com>
Acked-by: NRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20211216111654.238086-3-miquel.raynal@bootlin.com

Documentation/devicetree/bindings/mtd/nand-controller.yaml

@@ -184,7 +184,7 @@ examples:
         nand-use-soft-ecc-engine;
         nand-ecc-algo = "bch";
 
-        /* controller specific properties */
+        /* NAND chip specific properties */
       };
 
       nand@1 {