Merge r211111 from head:

Merge r211111 from head:

  Attempt to autodetect the cype of chipset, rather than storing this
  within the device table.  This code uses the same algorithm as used in
  the  Linux, NetBSD and DragonflyBSD driver.

  While investigating this, it became apparent that the Linux driver
  always initialises the device, and not just in the PL2303HX case.
  Change uplcom(4) to do the same.

  This change allows us to synchronize our device ID list with Linux and
  NetBSD, without requiring knowledge of the chipset in use.

Merge r209967, 209968 from head (by takawata):

  One more Prolific serial device ID.

git-svn-id: svn://svn.freebsd.org/base/stable/8@213052 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f