dt-bindings: Remove leading zeros from bindings notation

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

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

Converted using the following command:

perl -p -i -e 's/\@0+([0-9a-f])/\@$1/g' `find ./Documentation/devicetree/bindings "*.txt"`

Some unnecessary changes were manually fixed.

Signed-off-by: Marco Franchi <marco.franchi@nxp.com>
Signed-off-by: Rob Herring <robh@kernel.org>