staging: comedi: addi_apci_1032: conform to new INSN_CONFIG_DIGITAL_TRIG

staging: comedi: addi_apci_1032: conform to new INSN_CONFIG_DIGITAL_TRIG

Conform to the new definition of the `INSN_CONFIG_DIGITAL_TRIG`
configuration instruction.

Return an error if the 'trigger number' in `data[1]` is non-zero or if
the configuration operation in `data[2]` is not supported.  Deal with
the 'left-shift' amount in `data[3]`.

The trigger's input channels can only be configured as a set of rising
and falling edges ('OR' mode) or as a set of high and low levels ('AND'
mode).  Preserve the old input channels to the right of the 'left-shift'
value except when switching modes.

(The 'left-shift' support is a bit of an overkill for this driver since
the trigger only has 16 input channels.)

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>