arm64: dts: imx8dxl-ss-conn: Complete the FEC compatibles

Use the full compatible list for the imx8dl FEC as per fsl,fec.yaml.

This fixes the following schema warning:

imx8dxl-evk.dtb: ethernet@5b040000: compatible: 'oneOf' conditional failed, one must be fixed:
	['fsl,imx8qm-fec'] is too short
	'fsl,imx8qm-fec' is not one of ['fsl,imx25-fec', 'fsl,imx27-fec', 'fsl,imx28-fec', 'fsl,imx6q-fec', 'fsl,mvf600-fec', 'fsl,s32v234-fec']
	'fsl,imx8qm-fec' is not one of ['fsl,imx53-fec', 'fsl,imx6sl-fec']
	'fsl,imx8qm-fec' is not one of ['fsl,imx35-fec', 'fsl,imx51-fec']
	'fsl,imx8qm-fec' is not one of ['fsl,imx6ul-fec', 'fsl,imx6sx-fec']
	'fsl,imx8qm-fec' is not one of ['fsl,imx7d-fec']
	'fsl,imx8mq-fec' was expected
	'fsl,imx8qm-fec' is not one of ['fsl,imx8mm-fec', 'fsl,imx8mn-fec', 'fsl,imx8mp-fec', 'fsl,imx93-fec']
	'fsl,imx8qm-fec' is not one of ['fsl,imx8dxl-fec', 'fsl,imx8qxp-fec']
	'fsl,imx8qm-fec' is not one of ['fsl,imx8ulp-fec']
	from schema $id: http://devicetree.org/schemas/net/fsl,fec.yaml#Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8dxl-ss-conn.dtsi

@@ -118,7 +118,7 @@ &enet0_lpcg {
 };
 
 &fec1 {
-	compatible = "fsl,imx8qm-fec";
+	compatible = "fsl,imx8dxl-fec", "fsl,imx8qm-fec", "fsl,imx6sx-fec";
 	interrupts = <GIC_SPI 160 IRQ_TYPE_LEVEL_HIGH>,
 		     <GIC_SPI 158 IRQ_TYPE_LEVEL_HIGH>,
 		     <GIC_SPI 159 IRQ_TYPE_LEVEL_HIGH>,