arm64: dts: freescale: imx8m*-venice: remove label = "cpu" from DSA dt-binding

This is not used by the DSA dt-binding, so remove it from the devicetrees.
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts

@@ -678,7 +678,6 @@ lan4: port@3 {
 
 			port@5 {
 				reg = <5>;
-				label = "cpu";
 				ethernet = <&fec1>;
 				phy-mode = "rgmii-id";
 

arch/arm64/boot/dts/freescale/imx8mp-venice-gw74xx.dts

@@ -512,7 +512,6 @@ lan5: port@4 {
 
 			port@5 {
 				reg = <5>;
-				label = "cpu";
 				ethernet = <&fec>;
 				phy-mode = "rgmii-id";