timekeeper: fix comment typo for tk_setup_internals()

Fix trivial comment typo for tk_setup_internals().
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

kernel/time/timekeeping.c

@@ -90,8 +90,9 @@ static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
 }
 
 /**
- * timekeeper_setup_internals - Set up internals to use clocksource clock.
+ * tk_setup_internals - Set up internals to use clocksource clock.
  *
+ * @tk:		The target timekeeper to setup.
  * @clock:		Pointer to clocksource.
  *
  * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment