staging: comedi: quatech_daqp_cs: tidy up control register bits

For aesthetics, move the bit defines for this register and use the
BIT macro to define the bits. Rename the defines to match the
register.

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>