staging: comedi: pcmad: tidy up multi-line comments

Tidy up the multi-line comments at the beginning of the file to
follow the CodingStyle.

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>