staging: comedi: me_daq: use plx9052.h defines

Use the PLX 9052 register defines in plx9052.h instead of using
magic numbers for the register bits.

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>