cpufreq: ti: Implement scope-based cleanup in ti_cpufreq_match_node()

Modify the ti_cpufreq_match_node() function to utilize the __free()
cleanup handler for automatically releasing the device node when it goes
out of scope.

By moving the declaration to the initialization, the patch ensures that
the device node is properly managed throughout the function's scope,
thus eliminating the need for manual invocation of of_node_put().
This approach reduces the potential for memory leaks.

Suggested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Shivani Gupta <shivani07g@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>