Read and write desaturation from OSTC3's

This adds missing code to read and write the desaturation factor to and
from OSTC3's.

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
255% as limit for Saturation/Desaturation on OSTC3

The default max value for a QSpinBox is 99. The default Saturation
factor for the OSTC3 is 110%. This code raises the max values to 255
which is as far as i've read the ostc3_interface.odt the max value.

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Remove double include

Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>