MFC r272721:
  Fix a long standing bug in MAC statistics register access.  One
  additional register was erroneously added in the MAC register set
  such that 7 TX statistics counters were wrong.

(cherry picked from commit d91cb8dd6c039f8c6771c0554f3b18a40da2441e)
MFC r272730,273018:
  Add support for QAC AR816x/AR817x Gigabit/Fast Ethernet controllers.
  These controllers seem to have the same feature of AR813x/AR815x and
  improved RSS support(4 TX queues and 8 RX queues).  alc(4) supports
  all hardware features except RSS.  I didn't implement RX checksum
  offloading for AR816x/AR817x just because I couldn't get
  confirmation from the Vendor whether AR816x/AR817x corrected its
  predecessor's RX checksum offloading bug on fragmented packets.
  This change adds supports for the following controllers.
   o AR8161 PCIe Gigabit Ethernet controller
   o AR8162 PCIe Fast Ethernet controller
   o AR8171 PCIe Gigabit Ethernet controller
   o AR8172 PCIe Fast Ethernet controller
   o Killer E2200 Gigabit Ethernet controller

(cherry picked from commit 0fd564e87fcb68c9674b2c5eafef1e38942dda56)

Ticket: #3298