MFC: r182060
MFC: r182060

- Restore the behavior of enabling the MII buffer for an internal
  PHY only and not also in the case of an external PHY currently
  doing full duplex, which accidentally got broken in r180504.
  It's still not clear to me why we need to enable the buffer for
  an internal PHY though.
- Count excess and late collisions as output errors. [1]
- Count receive errors as input errors. [1]

Obtained from:	NetBSD [1]

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase