ath79: ar9330.dtsi: fix typo in USB unit name

Make the unitname match the reg address.  This fixes a DTC warning.

Tested that USB is still functional on an ar9331 device including this
dtsi.

Signed-off-by: Karl Palsson <[email protected]>

target/linux/ath79/dts/ar9330.dtsi

@@ -76,7 +76,7 @@
 			};
 		};
 
-		usb: usb@1b000100 {
+		usb: usb@1b000000 {
 			compatible = "chipidea,usb2";
 			reg = <0x1b000000 0x200>;