staging: mt7621-dts: fix switch0@0 warnings

Remove reg property from ports node to fix this warning:

Warning (unit_address_vs_reg): /ethernet@1e100000/mdio-bus/switch0@0/ports: node has a reg or ranges property, but no unit name

Another warning surfaces afterwards. Remove #address-cells and #size-cells
from switch0@0 node to fix this warning:

Warning (avoid_unnecessary_addr_size): /ethernet@1e100000/mdio-bus/switch0@0: unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Link: https://lore.kernel.org/r/20220125153903.1469-3-arinc.unal@arinc9.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-dts/mt7621.dtsi

@@ -360,8 +360,6 @@ phy_external: ethernet-phy@5 {
 
 			switch0: switch0@0 {
 				compatible = "mediatek,mt7621";
-				#address-cells = <1>;
-				#size-cells = <0>;
 				reg = <0>;
 				mediatek,mcm;
 				resets = <&rstctrl 2>;
@@ -374,7 +372,6 @@ switch0: switch0@0 {
 				ports {
 					#address-cells = <1>;
 					#size-cells = <0>;
-					reg = <0>;
 
 					port@0 {
 						status = "off";