ARM: zynq: dts: add description of the second uart

The zynq-7000 has an additional UART at 0xE0001000.  Describe it in the
device tree.
Signed-off-by: Josh Cartwright <josh.cartwright@ni.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-ep107.dts

@@ -59,5 +59,12 @@ uart0: uart@e0000000 {
 			interrupts = <0 27 4>;
 			clock = <50000000>;
 		};
+
+		uart1: uart@e0001000 {
+			compatible = "xlnx,xuartps";
+			reg = <0xE0001000 0x1000>;
+			interrupts = <0 50 4>;
+			clock = <50000000>;
+		};
 	};
 };