arm64: dts: socfpga: agilex: 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_agilex.dtsi:141.20-146.5: 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/intel/socfpga_agilex.dtsi

@@ -60,6 +60,13 @@ cpu3: cpu@3 {
 		};
 	};
 
+	fpga-region {
+		compatible = "fpga-region";
+		#address-cells = <0x2>;
+		#size-cells = <0x2>;
+		fpga-mgr = <&fpga_mgr>;
+	};
+
 	pmu {
 		compatible = "arm,armv8-pmuv3";
 		interrupts = <GIC_SPI 170 IRQ_TYPE_LEVEL_HIGH>,
@@ -138,13 +145,6 @@ 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,agilex-clkmgr";
 			reg = <0xffd10000 0x1000>;