staging: comedi: addi_apci_1500: rewrite the subdevice support functions

This driver is a mess. It violates the comedi API so much that I doubt
anything actually works.

Drop the addi-data/hwdrv_apci1500.c file and rewrite the subdevice support
functions.

This board has 16 digital inputs (subdevice 0) and 16 digital outputs
(subdevice 1).

It also has three 16-bit timer/counters provided by a Z8536 CIO chip
(subdevice 2). The Z8536 chip is also used to support pattern match
interrupt detection of the first 14 digital input channels.

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>