staging: comedi: addi_apci_1032: add a subdevice for the interrupt support

This board supports a single interrupt that can be generated by an AND/OR
combination of 16 of the input channels.

Create a separate subdevice, similar to the comedi_parport driver, to
handle this interrupt.

Move the i_APCI1032_ConfigDigitalInput() operation from the digital
input subdevice to this new subdevice. Rename the CamelCase function
to apci1032_intr_insn_config().

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