ARM: dts: ast2600: Make WDT by default disabled

The WDT devices described in the general .dtsi file
should be marked as "disabled" by default.

A WDT should be then enabled in the board specific
.dts file on demands.

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
diff --git a/arch/arm/dts/ast2600.dtsi b/arch/arm/dts/ast2600.dtsi
index ac0f08b..f121f54 100644
--- a/arch/arm/dts/ast2600.dtsi
+++ b/arch/arm/dts/ast2600.dtsi
@@ -474,21 +474,25 @@
 			wdt1: watchdog@1e785000 {
 				compatible = "aspeed,ast2600-wdt";
 				reg = <0x1e785000 0x40>;
+				status = "disabled";
 			};
 
 			wdt2: watchdog@1e785040 {
 				compatible = "aspeed,ast2600-wdt";
 				reg = <0x1e785040 0x40>;
+				status = "disabled";
 			};
 
 			wdt3: watchdog@1e785080 {
 				compatible = "aspeed,ast2600-wdt";
 				reg = <0x1e785080 0x40>;
+				status = "disabled";
 			};
 
 			wdt4: watchdog@1e7850C0 {
 				compatible = "aspeed,ast2600-wdt";
 				reg = <0x1e7850C0 0x40>;
+				status = "disabled";
 			};
 
 			lpc: lpc@1e789000 {