staging: comedi: drivers: remove unnecessary *_{IO, MEM}SIZE defines

Some of the legacy comedi drivers have a *_{IO,MEM}SIZE define that is
only passed to comedi_request_region() to specify the size of the region.

For aesthetics, remove these defines.

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