powerpc: dts: turris1x.dts: Fix labels in DSA cpu port nodes

DSA cpu port node has to be marked with "cpu" label.
So fix it for both cpu port nodes.

Fixes: 54c15ec3 ("powerpc: dts: Add DTS file for CZ.NIC Turris 1.x routers")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220827131538.14577-1-pali@kernel.org

arch/powerpc/boot/dts/turris1x.dts

@@ -147,7 +147,7 @@ ports {
 
 					port@0 {
 						reg = <0>;
-						label = "cpu1";
+						label = "cpu";
 						ethernet = <&enet1>;
 						phy-mode = "rgmii-id";
 
@@ -184,7 +184,7 @@ port@5 {
 
 					port@6 {
 						reg = <6>;
-						label = "cpu0";
+						label = "cpu";
 						ethernet = <&enet0>;
 						phy-mode = "rgmii-id";