* @index: clock type index for per_cpu support when moving a
* timer to a base on another cpu.
* @active: red black tree root node for the active timers
- * @first: pointer to the timer node which expires first
* @resolution: the resolution of the clock, in nanoseconds
* @get_time: function to retrieve the current time of the clock
* @softirq_time: the time when running the hrtimer queue in the softirq