There are various open coded implementions parsing the CPU node 'reg' property which contains the CPU's hardware ID. Introduce a new function, of_get_cpu_hwid(), to read the hardware ID. All the callers should be DT only code, so no need for an empty function. Cc: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Rob Herring <robh@kernel.org> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20211006164332.1981454-2-robh@kernel.org