MFC overview:

MFC overview:
- Fix busg in events provided to devd from the USB stack.
- Provide more info on the u3g devices that attached.
- Make the ucom device numbering more sane.

MFC r214429

Add support for setting per-interface PnP information.

MFC r214761

- Simplify the way unit/subunit allocation is done in ucom.
- hw.usb.ucom.cons_unit is now split into
  hw.usb.ucom.cons_unit/...cons_subunit.

  Note: The tunable/sysctl hw.usb.ucom.cons_unit needs to be reviewed if

  a) a console was defined a USB serial devices, and a USB device with
  more than 1 subunit is present, and this device is attached before the
  device functioning as a console

  or

  b) a console was defined on a USB device with more than 1 subunit

MFC r214809

  Don't terminate the notification with \n. This is done in
  usb_device.c:devctl_notify_f().

MFC r214830

Bugfix: Move the 'at <location string' to the beginning of the attach
notification. devd would stop evaluating at 'at' (not '<k>=<v>') and
hence prevent 'port=X' (and 'bus=<"on" string>) from making it into the
environment for the devd action.

MFC r214831

- Remove an unused entry from the softc (only used in a debugging printf).
- Fix the loop count on detach (causing a panic on detaching a serial
  dongle).
- Increase a buffer in case some driver want extra long tty device names
  (postfixing the purpose of the tty for example, e.g. u3g.ppp).

MFC r214843

Implement ucom_set_pnpinfo_usb() providing ttyname and port number
information through devd. My E220 now produces the notification (1 line):

        +u3g0 at bus=1 hubaddr=1 port=0 devaddr=2 interface=0 \
        vendor=0x12d1 product=0x1003 devclass=0x00 devsubclass=0x00 \
        sernum="" release=0x0000 intclass=0xff intsubclass=0xff \
        ttyname=U0 ttyports=2 on uhub0

Note: serial/ufoma and net/uhso still provide port number and tty name
(uhso only) information through sysctls, which should now be removed.

MFC r214919

Bugfix: Set the bit that marks a device number in use.
This would cause a panic when disconnecting the second serial device.

git-svn-id: svn://svn.freebsd.org/base/stable/8@221612 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f