Documentation: fsl-quadspi: Add fsl, ls2080a-qspi compatible string

new compatible string: "fsl,ls2080a-qspi".
Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Han xu <han.xu@nxp.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Documentation/devicetree/bindings/mtd/fsl-quadspi.txt

@@ -3,7 +3,9 @@
 Required properties:
   - compatible : Should be "fsl,vf610-qspi", "fsl,imx6sx-qspi",
 		 "fsl,imx7d-qspi", "fsl,imx6ul-qspi",
-		 "fsl,ls1021-qspi"
+		 "fsl,ls1021a-qspi"
+		 or
+		 "fsl,ls2080a-qspi" followed by "fsl,ls1021a-qspi"
   - reg : the first contains the register location and length,
           the second contains the memory mapping address and length
   - reg-names: Should contain the reg names "QuadSPI" and "QuadSPI-memory"