ARM: zynq: DT: Use 0x prefix for memory nodes

Be align with the rest of zynq DTS and have 0
written as 0x0.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-parallella.dts

@@ -25,7 +25,7 @@ / {
 
 	memory {
 		device_type = "memory";
-		reg = <0 0x40000000>;
+		reg = <0x0 0x40000000>;
 	};
 
 	chosen {

arch/arm/boot/dts/zynq-zc706.dts

@@ -20,7 +20,7 @@ / {
 
 	memory {
 		device_type = "memory";
-		reg = <0 0x40000000>;
+		reg = <0x0 0x40000000>;
 	};
 
 	chosen {

arch/arm/boot/dts/zynq-zed.dts

@@ -20,7 +20,7 @@ / {
 
 	memory {
 		device_type = "memory";
-		reg = <0 0x20000000>;
+		reg = <0x0 0x20000000>;
 	};
 
 	chosen {