arm64: dts: socfpga: stratix10: move FPGA region out of soc node

The "soc" node is supposed to have only MMIO children, so move the FPGA
region node to top level to fix dtc W=1 warnings like:

  socfpga_stratix10.dtsi:136.20-141.5: Warning (simple_bus_reg): /soc@0/base_fpga_region: missing or empty reg/ranges property
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm64/boot/dts/altera/socfpga_stratix10.dtsi

@@ -59,6 +59,13 @@ cpu3: cpu@3 {
 		};
 	};
 
+	fpga-region {
+		compatible = "fpga-region";
+		#address-cells = <0x2>;
+		#size-cells = <0x2>;
+		fpga-mgr = <&fpga_mgr>;
+	};
+
 	pmu {
 		compatible = "arm,armv8-pmuv3";
 		interrupts = <0 170 4>,
@@ -133,13 +140,6 @@ soc {
 		interrupt-parent = <&intc>;
 		ranges = <0 0 0 0xffffffff>;
 
-		base_fpga_region {
-			#address-cells = <0x2>;
-			#size-cells = <0x2>;
-			compatible = "fpga-region";
-			fpga-mgr = <&fpga_mgr>;
-		};
-
 		clkmgr: clock-controller@ffd10000 {
 			compatible = "intel,stratix10-clkmgr";
 			reg = <0xffd10000 0x1000>;