MFC r251482,251733:

MFC r251482,251733:
r251482:
  Correct setting TX random backoff register. This register is
  implemented as a 10 bits linear feedback shift register so only
  lower 10 bits are valid.
  Because this register is used to initialize random backoff interval
  register only when resolved duplex is half-duplex, it wouldn't have
  caused issues in these days.

r251733:
  Fix a typo introduced in r213280. IFM_OPTIONS macro should see
  current media word.

git-svn-id: svn://svn.freebsd.org/base/stable/8@252456 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f