dt-bindings: mtd: mchp48l640 add mb85rs128ty compatible

Add a compatible string to support Fujitsu MB85RS128TY.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jonas Rebmann <jre@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Author: jonrebm

Documentation/devicetree/bindings/mtd/microchip,mchp48l640.yaml

@@ -16,8 +16,9 @@ description: |
 
 properties:
   compatible:
-    items:
-      - const: microchip,48l640
+    enum:
+      - fujitsu,mb85rs128ty
+      - microchip,48l640
 
   reg:
     maxItems: 1