ARM: dts: aspeed: Update watchdog compatible strings

The string was changed when upstreaming the driver. Put the correct
string for generation 4 and 5 systems, as well as fix the reg length for
ast2500 systems.
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/aspeed-g4.dtsi

@@ -898,13 +898,13 @@ timer: timer@1e782000 {
 			};
 
 			wdt1: wdt@1e785000 {
-				compatible = "aspeed,wdt";
+				compatible = "aspeed,ast2400-wdt";
 				reg = <0x1e785000 0x1c>;
 				interrupts = <27>;
 			};
 
 			wdt2: wdt@1e785020 {
-				compatible = "aspeed,wdt";
+				compatible = "aspeed,ast2400-wdt";
 				reg = <0x1e785020 0x1c>;
 				interrupts = <27>;
 				clocks = <&clk_apb>;

arch/arm/boot/dts/aspeed-g5.dtsi

@@ -1007,21 +1007,21 @@ timer: timer@1e782000 {
 
 
 			wdt1: wdt@1e785000 {
-				compatible = "aspeed,wdt";
-				reg = <0x1e785000 0x1c>;
+				compatible = "aspeed,ast2500-wdt";
+				reg = <0x1e785000 0x20>;
 				interrupts = <27>;
 			};
 
 			wdt2: wdt@1e785020 {
-				compatible = "aspeed,wdt";
-				reg = <0x1e785020 0x1c>;
+				compatible = "aspeed,ast2500-wdt";
+				reg = <0x1e785020 0x20>;
 				interrupts = <27>;
 				status = "disabled";
 			};
 
 			wdt3: wdt@1e785040 {
-				compatible = "aspeed,wdt";
-				reg = <0x1e785074 0x1c>;
+				compatible = "aspeed,ast2500-wdt";
+				reg = <0x1e785040 0x20>;
 				status = "disabled";
 			};