staging: comedi: adv_pci1723: fix initial dio subdevice state and io_bits

The initial state and io_bits for the dio subdevice is determined in
the pci1723_attach() but it's being saved in the wrong subdevice. Move
the code so it gets saved correctly.

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>