staging: comedi: me4000: make boardinfo flags bit-fields

Change the boardinfo 'has_counter' and 'ai_trig_analog' flags into
bit-fields to save a bit of space.

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>