arm64: dts: ls1028a: mark enetc port 3 as a DSA master too

The LS1028A switch has 2 internal links to the ENETC controller.

With DSA's ability to support multiple CPU ports, we should mark both
ENETC ports as DSA masters.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi

@@ -1169,6 +1169,7 @@ fixed-link {
 					mscc_felix_port5: port@5 {
 						reg = <5>;
 						phy-mode = "internal";
+						ethernet = <&enetc_port3>;
 						status = "disabled";
 
 						fixed-link {