staging: comedi: ni_pcimio: use comedi provided range_bipolar10

Remove the private range, range_ni_M_622x_ao, in this driver and use
the comedi provided range_bipolar10 instead.

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>