staging: comedi: drivers: amplc_pci230: make bool bit-field unsigned int bit-fields.

Checkpatch complains on bool bitfields to be an int or u8/u16/u32
bitfield.

Make bool bit-fields to be unsigned int bit-fields.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>