cmhw: add DisplayColorCalibration tunables

Change-Id: Ifb49365d95507f886a70e96c72697b5a5618c073
DisplayColorCalibration: Increase range

Along with associated kernel patch, increases the range of the display
tuner. Adjusts the "/sys/class/misc/gammacontrol/tuner" node to contain
an RGB triplet from 0 to 120, with "60 60 60" being nominal values

Individual gamma corrections can be also be found by tweaking the nodes
in /sys/class/misc/gammacontrol

Change-Id: Iad498fe8e89fe135e968f78b096a3d1c85c0a4ab