staging: comedi: ii_pci20kc: cleanup final pieces

Tidy up the multi-line comments at the beginning of the file and
remove any irrelevant information.

Fix the II20K_ID_PCI200341M_1 define, there are one to many 0's.

Rename all the remaining pci20xxx_* to ii20k_*. The "pci" just adds
confusion, this is not a PCI board.

Remove the private (*detach) function. It's safe to call the comedi
core provided comedi_legacy_detach() even if there is nothing to
cleanup.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>