dt-bindings: Remove leading 0x from bindings notation

Improve the binding example by removing all the leading 0x to fix the
following dtc warnings:

Warning (unit_address_format): Node /XXX unit name should not have leading "0x"

Converted using the following command:

find Documentation/devicetree/bindings -name "*.txt" -exec sed -i -e 's/([^ ])\@0x([0-9a-f])/$1\@$2/g' {} +

This is a follow up to commit 48c926cd34

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt

@@ -45,7 +45,7 @@ Optional properties:
 - usb3_vbus-supply : regulator phandle for controller usb3 vbus
 
 Example:
-	usbphy: phy@0x01c13400 {
+	usbphy: phy@01c13400 {
 		#phy-cells = <1>;
 		compatible = "allwinner,sun4i-a10-usb-phy";
 		/* phy base regs, phy1 pmu reg, phy2 pmu reg */