staging: comedi: amplc_dio200: Use IS_ENABLED()

Change conditional compilation on kernel options to use the IS_ENABLED()
macro.  Remove most of the #ifdef lines and add extra if
(IS_ENABLED(xxx)) tests so the compiler can remove unreachable code.
The pci_driver stuff and device table and some of the static const data
is still conditionally compiled.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>