dt-bindings: arm: fsl-scu: Add imx8dxl pinctrl support

Update binding doc to support i.MX8DXL pinctrl.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1585306559-13973-1-git-send-email-Anson.Huang@nxp.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt

@@ -108,7 +108,8 @@ This binding uses the i.MX common pinctrl binding[3].
 Required properties:
 - compatible:		Should be one of:
 			"fsl,imx8qm-iomuxc",
-			"fsl,imx8qxp-iomuxc".
+			"fsl,imx8qxp-iomuxc",
+			"fsl,imx8dxl-iomuxc".
 
 Required properties for Pinctrl sub nodes:
 - fsl,pins:		Each entry consists of 3 integers which represents
@@ -116,7 +117,8 @@ Required properties for Pinctrl sub nodes:
 			integers <pin_id mux_mode> are specified using a
 			PIN_FUNC_ID macro, which can be found in
 			<dt-bindings/pinctrl/pads-imx8qm.h>,
-			<dt-bindings/pinctrl/pads-imx8qxp.h>.
+			<dt-bindings/pinctrl/pads-imx8qxp.h>,
+			<dt-bindings/pinctrl/pads-imx8dxl.h>.
 			The last integer CONFIG is the pad setting value like
 			pull-up on this pin.