kqueue for usb_dev

[Hans Petter Selasky]

Hi Kohji,

Can you verify this commit:

http://svnweb.freebsd.org/changeset/base/262550

Please test using both read and write direction. For example you can use 
the ULPT driver or a /dev/usb/X.X.X node which supports both read and write.

Thank you!

--HPS