ARM: dts: Updated devicetree bindings for Zynq 7000 platform

Added addtional bindings required for FPGA Manager operation
of the Xilinx Zynq Devc configuration interface.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/dts/zynq-7000.dtsi b/arch/arm/dts/zynq-7000.dtsi
index 55eae61..aff65f2 100644
--- a/arch/arm/dts/zynq-7000.dtsi
+++ b/arch/arm/dts/zynq-7000.dtsi
@@ -307,6 +307,7 @@
 		devcfg: devcfg@f8007000 {
 			compatible = "xlnx,zynq-devcfg-1.0";
 			reg = <0xf8007000 0x100>;
+			syscon = <&slcr>;
 		};
 
 		global_timer: timer@f8f00200 {