Merge from NetBSD:

Merge from NetBSD:
o rev. 1.10: Nuke trailing whitespace.
o rev. 1.15: Fix typo in comment.
o rev. 1.16: Add the following registers from IEEE 802.3-2009 Clause 22:
 - PSE control register (0x0b)
 - PSE status register (0x0c)
 - MMD access control register (0x0d)
 - MMD access address data register (0x0e)
o rev. 1.17 (comments only): The bit location of link ability is different
  between 1000Base-X and others (see Annex 28B.2 and 28D).
o rev. 1.18: Nuke dupe word.

Obtained from:	NetBSD
MFC after:	1 week
Sponsored by:	genua mbh