dt-bindings: nvmem: mxs-ocotp: Document fsl,ocotp

Both imx23.dtsi and imx28.dtsi describe the OCOTP nodes in
the format:

compatible = "fsl,imx28-ocotp", "fsl,ocotp";

Document the "fsl,ocotp" entry to fix the following schema
warning:

efuse@8002c000: compatible: ['fsl,imx23-ocotp', 'fsl,ocotp'] is too long
from schema $id: http://devicetree.org/schemas/nvmem/mxs-ocotp.yaml#

Fixes: 2c504460 ("dt-bindings: nvmem: Convert MXS OCOTP to json-schema")
Cc:  <Stable@vger.kernel.org>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111358.316727-2-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/nvmem/mxs-ocotp.yaml

@@ -15,9 +15,11 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - fsl,imx23-ocotp
-      - fsl,imx28-ocotp
+    items:
+      - enum:
+          - fsl,imx23-ocotp
+          - fsl,imx28-ocotp
+      - const: fsl,ocotp
 
   reg:
     maxItems: 1
@@ -35,7 +37,7 @@ unevaluatedProperties: false
 examples:
   - |
     ocotp: efuse@8002c000 {
-        compatible = "fsl,imx28-ocotp";
+        compatible = "fsl,imx28-ocotp", "fsl,ocotp";
         #address-cells = <1>;
         #size-cells = <1>;
         reg = <0x8002c000 0x2000>;