staging: comedi: adv_pci1723: absorb pci1723_reset()

This function is only called by the (*auto_attach) to reset all the analog
output channels. For aesthetics, absorb the function.

Fix the range programming for each channel. According to the users manual
the "range strobe" register needs to be written after setting the "DAC range
control" register in order to load the range setting.

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>