ARM: dts: aspeed-g6: Cleanup watchdog unit address

arch/arm/boot/dts/aspeed-g6.dtsi:204.28-208.6: Warning (simple_bus_reg): /ahb/apb/watchdog@1e7850C0: simple-bus unit address format error, expected "1e7850c0"
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/aspeed-g6.dtsi

@@ -385,7 +385,7 @@ wdt3: watchdog@1e785080 {
 				status = "disabled";
 			};
 
-			wdt4: watchdog@1e7850C0 {
+			wdt4: watchdog@1e7850c0 {
 				compatible = "aspeed,ast2600-wdt";
 				reg = <0x1e7850C0 0x40>;
 				status = "disabled";