esp_system: link time, not runtime, dependency on esp_timer

components/esp_timer/private_include/esp_timer_impl.h

@@ -117,8 +117,3 @@ uint64_t esp_timer_impl_get_counter_reg(void);
  * @return the value of the alarm register
  */
 uint64_t esp_timer_impl_get_alarm_reg(void);
-
-/**
- * @brief Initialize and provide system timekeeping functions.
- */
-esp_err_t esp_timer_timekeeping_impl_init(void);