arm: dt: zynq: Use 'status' property for UART nodes

Set the default status for UARTs to disabled in the zynq-7000.dtsi file
and let board dts files enable the UARTs on demand.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-7000.dtsi

@@ -49,6 +49,7 @@ L2: cache-controller {
 
 		uart0: uart@e0000000 {
 			compatible = "xlnx,xuartps";
+			status = "disabled";
 			clocks = <&clkc 23>, <&clkc 40>;
 			clock-names = "ref_clk", "aper_clk";
 			reg = <0xE0000000 0x1000>;
@@ -57,6 +58,7 @@ uart0: uart@e0000000 {
 
 		uart1: uart@e0001000 {
 			compatible = "xlnx,xuartps";
+			status = "disabled";
 			clocks = <&clkc 24>, <&clkc 41>;
 			clock-names = "ref_clk", "aper_clk";
 			reg = <0xE0001000 0x1000>;

arch/arm/boot/dts/zynq-zc702.dts

@@ -24,7 +24,11 @@ memory {
 	};
 
 	chosen {
-		bootargs = "console=ttyPS1,115200 earlyprintk";
+		bootargs = "console=ttyPS0,115200 earlyprintk";
 	};
 
 };
+
+&uart1 {
+	status = "okay";
+};