staging: comedi: ni_labpc_cs: move comedi_driver declaration

Move the comedi_driver declaration down in the file. This removes
the need for the forward declaration.

For aesthetic reasons, add some whitespace to the declaration and
remove the unnecessary '&' before the function names. They are
already addresses.

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>