dt-bindings: mtd: mxc-nand: add missing compatible string and ref to nand-controller-legacy.yaml

Add compatible string fsl,imx51-nand, fsl,imx53-nand and fsl,imx35-nand.

Add missinge properties dmas and dma-names.

Change reg's maxItems to 2 because i.MX53 have addition NAND flash internal
buffer space.

Change ref to nand-controller-legacy.yaml allow legacy DT layout.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

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

@@ -10,7 +10,7 @@ maintainers:
   - Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
 
 allOf:
-  - $ref: nand-controller.yaml
+  - $ref: nand-controller-legacy.yaml
 
 properties:
   compatible:
@@ -18,12 +18,21 @@ properties:
       - enum:
           - fsl,imx25-nand
           - fsl,imx27-nand
+          - fsl,imx51-nand
+          - fsl,imx53-nand
+      - items:
+          - enum:
+              - fsl,imx35-nand
+          - const: fsl,imx25-nand
       - items:
           - enum:
               - fsl,imx31-nand
           - const: fsl,imx27-nand
   reg:
-    maxItems: 1
+    minItems: 1
+    items:
+      - description: IP register space
+      - description: Nand flash internal buffer space
 
   interrupts:
     maxItems: 1
@@ -31,6 +40,13 @@ properties:
   clocks:
     maxItems: 1
 
+  dmas:
+    maxItems: 1
+
+  dma-names:
+    items:
+      - const: rx-tx
+
 required:
   - compatible
   - reg