staging: comedi: me4000: all board types have analog inputs

All the boards supported by this driver have analog inputs. They just
differ in the number of channels (32 or 16).

Always initialize the analog input subdevice in me4000_auto_attach().

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>