sandbox: Update PCI nodes in dts files

The way the PCI nodes are written today causes a number of warnings if
we stop disabling some of the warnings we pass to DTC.  As these
warnings aren't disabled in current Linux Kernel builds, we should aim
to not disable them here either, so rewrite these slightly.  Update the
driver model doc as well.

Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 4a27793..2338064 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -463,9 +463,10 @@
 		compatible = "sandbox,pch";
 	};
 
-	pci0: pci-controller0 {
+	pci0: pci@0 {
 		compatible = "sandbox,pci";
 		device_type = "pci";
+		bus-range = <0x00 0xff>;
 		#address-cells = <3>;
 		#size-cells = <2>;
 		ranges = <0x02000000 0 0x10000000 0x10000000 0 0x2000000
@@ -531,9 +532,10 @@
 		};
 	};
 
-	pci1: pci-controller1 {
+	pci1: pci@1 {
 		compatible = "sandbox,pci";
 		device_type = "pci";
+		bus-range = <0x00 0xff>;
 		#address-cells = <3>;
 		#size-cells = <2>;
 		ranges = <0x02000000 0 0x30000000 0x30000000 0 0x2000
@@ -546,9 +548,10 @@
 		};
 	};
 
-	pci2: pci-controller2 {
+	pci2: pci@2 {
 		compatible = "sandbox,pci";
 		device_type = "pci";
+		bus-range = <0x00 0xff>;
 		#address-cells = <3>;
 		#size-cells = <2>;
 		ranges = <0x02000000 0 0x50000000 0x50000000 0 0x2000