staging: comedi: addi_apci_3501: separate from addi_common.c

This driver is for a simple analog output board with 4 or 8, 14-bit
outputs. The board also has 4 digital i/o channels (2 out/2 in) as
well as a watchdog or timer. Using the addi-data "common" code in
this driver introduces a lot of bloat.

Copy the code in addi_common.c to this driver and remove the #include
that caused it to be compiled with the driver. This will allow removing
the bloat.

Rename the auto_attach and detach functions so they have namespace
associated with this driver.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>