extmod/utime_mphal: Implement ticks_add(), add to all maintained ports.
diff --git a/esp8266/modutime.c b/esp8266/modutime.c
index abfe069..f3dfc46 100644
--- a/esp8266/modutime.c
+++ b/esp8266/modutime.c
@@ -119,6 +119,7 @@
     { MP_OBJ_NEW_QSTR(MP_QSTR_ticks_ms), (mp_obj_t)&mp_utime_ticks_ms_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ticks_us), (mp_obj_t)&mp_utime_ticks_us_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ticks_cpu), (mp_obj_t)&mp_utime_ticks_cpu_obj },
+    { MP_ROM_QSTR(MP_QSTR_ticks_add), MP_ROM_PTR(&mp_utime_ticks_add_obj) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ticks_diff), (mp_obj_t)&mp_utime_ticks_diff_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&time_time_obj },
 };