staging: comedi: amplc_pci224: reformat some comments

Reformat comments to fit in with the preferred coding style, including
the copyright and comedi driver description comments at the start of the
file.  Also, remove a boiler-plate comment for the comedi device private
data structure.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>