x86: qemu: Set up device tree for SPL

Add the correct pre-relocation tag so that the required device tree
nodes are present in the SPL device tree.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/x86/dts/qemu-x86_i440fx.dts

@@ -29,10 +29,12 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		u-boot,dm-pre-reloc;
 
 		cpu@0 {
 			device_type = "cpu";
 			compatible = "cpu-qemu";
+			u-boot,dm-pre-reloc;
 			reg = <0>;
 			intel,apic-id = <0>;
 		};
@@ -54,9 +56,11 @@
 		pch@1,0 {
 			reg = <0x00000800 0 0 0 0>;
 			compatible = "intel,pch7";
+			u-boot,dm-pre-reloc;
 
 			irq-router {
 				compatible = "intel,irq-router";
+				u-boot,dm-pre-reloc;
 				intel,pirq-config = "pci";
 				intel,pirq-link = <0x60 4>;
 				intel,pirq-mask = <0x0e40>;

arch/x86/dts/qemu-x86_q35.dts

@@ -40,10 +40,12 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		u-boot,dm-pre-reloc;
 
 		cpu@0 {
 			device_type = "cpu";
 			compatible = "cpu-qemu";
+			u-boot,dm-pre-reloc;
 			reg = <0>;
 			intel,apic-id = <0>;
 		};
@@ -65,9 +67,11 @@
 		pch@1f,0 {
 			reg = <0x0000f800 0 0 0 0>;
 			compatible = "intel,pch9";
+			u-boot,dm-pre-reloc;
 
 			irq-router {
 				compatible = "intel,irq-router";
+				u-boot,dm-pre-reloc;
 				intel,pirq-config = "pci";
 				intel,actl-8bit;
 				intel,actl-addr = <0x44>;