staging: comedi: addi_common.c: remove v_ADDI_Interrupt()

The addi_apci_035 and addi_apci_1500 are the only drivers left that use
this function in addi_common.c. The function simply calls the 'interrupt'
function that is in the boardinfo of the driver. Both drivers use the
same 'interrupt' function for all boardnfo entries.

Remove the i_ADDI_Reset() function as well as the 'interrupt' boardinfo
and use the 'interrupt' function directly when doing the request_irq().

In addition, the addi_apci_3120 driver has a private v_ADDI_Interrupt()
function that is doing the same thing. Remove that one as well.

Fix the return type of 'interrupt' functions in the drivers and add the
return vaules.

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>