airoha: an7583: update ethernet node for new PCS implementation

With new PCS implementation, the pcs property needs to be updated to the
new name of 'pcs-handle' to correctly work with PCS fwnode
consumer/provider.

Fixes: 4d5f579a81 ("airoha: update PCS node in DTSI for new PCS implementation")
Signed-off-by: Robert Marko <robert.marko@sartura.hr>

target/linux/airoha/dts/an7583.dtsi

@@ -671,7 +671,7 @@
 			gdm2: ethernet@2 {
 				compatible = "airoha,eth-mac";
 				reg = <2>;
-				pcs = <&pon_pcs>;
+				pcs-handle = <&pon_pcs>;
 
 				status = "disabled";
 			};
@@ -679,7 +679,7 @@
 			gdm3: ethernet@3 {
 				compatible = "airoha,eth-mac";
 				reg = <3>;
-				pcs = <&eth_pcs>;
+				pcs-handle = <&eth_pcs>;
 				airoha,gdm-srcport = <0x16>;
 
 				status = "disabled";