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/devfreq/event/rockchip-dfi.txt

@@ -9,7 +9,7 @@ Required properties:
 - clock-names : the name of clock used by the DFI, must be "pclk_ddr_mon";
 
 Example:
-	dfi: dfi@0xff630000 {
+	dfi: dfi@ff630000 {
 		compatible = "rockchip,rk3399-dfi";
 		reg = <0x00 0xff630000 0x00 0x4000>;
 		rockchip,pmu = <&pmugrf>;