Staging: comedi: addi-data: tidy up counter register map defines in hwdrv_apci1564.c

This patch fixes the register map defines for the counter registers such
that they are all the real offsets to each register, rather than a mix of
real offsets and adders to those offsets.
Signed-off-by: Chase Southwood <chase.southwood@yahoo.com>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>