[FS#559] No Ethernet statistics on ag71xx

[LEDE Bugs]

The following task is now closed:

FS#559 - No Ethernet statistics on ag71xx
User who did this - Yousong Zhou (yousong)

Reason for closing: No response
Additional comments about closing: Issue confirmed, but maybe let's reopen it when there is more interest and activity

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=559