staging: comedi: adv_pci1710: don't "reset" board when detaching

Currently this driver calls pci1710_reset() during the (*detach) of
the driver. That function does the following:

  1) program the control register to stop any operations
  2) clears the analog input FIFO
  3) clears any pending interrupts
  4) sets all the analog output channels to unipolar 5V range and 0V output
  5) sets all the digital outputs to 0V

Before detaching the comedi core will (*cancel) any running async commands.
This will handle 1-3 above.

Depending on the application, it might not be safe to reset the analog and
digital outputs when the driver is detached.

Remove the board reset when detaching and just use comedi_pci_detach()
directly for the driver (*detach).

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>