staging: comedi: Kconfig: COMEDI_NI_ATMIO should select COMEDI_FC

staging: comedi: Kconfig: COMEDI_NI_ATMIO should select COMEDI_FC

As pointed out by the kbuild test robot, the ni_atmio driver includes
ni_mio_common.c which uses the helper functions in the comedi_fc module.

Select the COMEDI_FC module when COMEDI_NI_ATMIO is enabled to fix the
following build error:

ERROR: "cfc_write_array_to_buffer" [drivers/staging/comedi/drivers/ni_atmio.ko] undefined!

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>