dt-bindings: opp: Re-organise kryo cpufreq to use it for other nvmem based qcom socs

The kryo cpufreq driver reads the nvmem cell and uses that data to
populate the opps. There are other qcom cpufreq socs like krait which
does similar thing. Except for the interpretation of the read data,
rest of the driver is same for both the cases. So pull the common things
out for reuse.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
[niklas.cassel@linaro.org: split dt-binding into a separate patch and
do not rename the compatible string.]
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Reviewed-by: Ilia Lin <ilia.lin@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>