staging: comedi: ni_mio_common: implement output selection of GPFO_{0, 1}

Implement the ability to route various signals to NI_CtrOut(x) pin.  This
pin is also known as GPFO_{0,1} in the DAQ STC.

Signed-off-by: Spencer E. Olson <olsonse@umich.edu>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>