cpufreq: tegra194: add online/offline hooks

Implement the light-weight tear down and bring up helpers to reduce the
amount of work to do on CPU offline/online operation.
This change helps to make the hotplugging paths much faster.

Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Link: https://lore.kernel.org/lkml/20230816033402.3abmugb5goypvllm@vireshk-i7/


[ Viresh: Fixed rebase conflict ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>