Gamma Control: change range

The current userspace implementation really hates negative numbers on
the slider bars. Let's accept 0 to 120, with nominal values achieved as
echo "60 60 60" > /sys/class/misc/gammacontrol/tuner and trinity blue as
"60 60 80"

Change-Id: Ic6768baf53997a5984e9470e423d080e64b217b5

Conflicts:
	drivers/misc/gamma_control.c