Use the kernel CRC routines rather than a do-it-yourself version.
By the way, I created a common USB Makefile.lib, rather than having
one for the class drivers, and one for speedtouch.

Eliminate a pile of code that isn't used anymore now the new send code
is in place, and make some cosmetic changes.

Expose some CRC definitions in atmsar.h (for use by speedtouch.c).

  speedtouch: add a new encoding function, atmsar_encode.  Calling it amounts to doing
  atmsar_encode_aal5 followed by atmsar_encode_rawcell in one fell swoop.  It eliminates
  the need for intermediate buffers and reduces memory movement.  The following patches
  use it to simplify the send logic (and get rid of those annoying little oopsen).

speedtouch and friends: add GPL notices (yes, the module was released by Alcatel
under the GPL) and fix some typos.

Patch originally from Richard Purdie <rpurdie@rpsys.net> but tweaked by me.