dt-bindings: mtd: rockchip: add rockchip,rk3128-nfc

Add rockchip,rk3128-nfc compatible string.

Signed-off-by: Johan Jonker <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/linux-mtd/[e-mail]

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

···
       - const: rockchip,rk2928-nfc
       - const: rockchip,rv1108-nfc
       - items:
-          - const: rockchip,rk3036-nfc
+          - enum:
+              - rockchip,rk3036-nfc
+              - rockchip,rk3128-nfc
           - const: rockchip,rk2928-nfc
       - items:
           - const: rockchip,rk3308-nfc