powerpc/boot/dts: Remove leading 0x and 0s from bindings notation

Improve the DTS files by removing all the leading "0x" and zeros to
fix the following dtc warnings:

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

and:

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

Converted using the following command:

  find . -type f \( -iname *.dts -o -iname *.dtsi \) -exec sed -E -i -e "s/@0x([0-9a-fA-F\.]+)\s?\{/@\L\1 \{/g" -e "s/@0+([0-9a-fA-F\.]+)\s?\{/@\L\1 \{/g" {} +

For simplicity, two sed expressions were used to solve each warnings
separately.

To make the regex expression more robust a few other issues were
resolved, namely setting unit-address to lower case, and adding a
whitespace before the the opening curly brace:

  https://elinux.org/Device_Tree_Linux#Linux_conventions



This is a follow up to commit 4c9847b7 ("dt-bindings: Remove
leading 0x from bindings notation")

Reported-by: David Daney <ddaney@caviumnetworks.com>
Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>