cpufreq: arm_big_little: remove device tree parsing for cpu nodes

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Git-commit: da0eb143dbbaf26b6f084bee81d56fc64efb5390
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Junjie Wu <junjiew@codeaurora.org>