clk: fix a typo in comment block of clk_notifier_register()

 * re-enter into the clk framework by calling any top-level clk APIs;

 * this will cause a nested prepare_lock mutex.

 *

 * In all notification cases cases (pre, post and abort rate change) the

 * original clock rate is passed to the callback via struct

 * clk_notifier_data.old_rate and the new frequency is passed via struct

 * clk_notifier_data.new_rate.

 * In all notification cases (pre, post and abort rate change) the original

 * clock rate is passed to the callback via struct clk_notifier_data.old_rate

 * and the new frequency is passed via struct clk_notifier_data.new_rate.

 *

 * clk_notifier_register() must be called from non-atomic context.

 * Returns -EINVAL if called with null arguments, -ENOMEM upon