mdnie lite control: add control interface
Compatible with mdnie lite engine used by samsung qualcomm variants i9505/n9005.

sysfs controls for RGBYCMWK channel and "sharpen" effect:
[sys/class/mdnie/mdnie/control_*]

[echo 255 150 75 > /sys/class/mdnie/mdnie/control_red]
(255 = red; 150 = green; 75 = blue)

[echo 250 235 255 > /sys/class/mdnie/mdnie/control_white]
(250 = red; 235 = green; 255 = blue)

override for all samsung modes and profiles is enabled by default:
[echo 1 > /sys/class/mdnie/mdnie/control_override]

small increase on black level (4 = 1,5% of 255] is intended to reduce black crush and smearing effects:
[echo 4 4 4 > /sys/class/mdnie/mdnie/control_black]

Idea based on (mDNIe colour and brightness control) by AndreiLux.
Credits to Yank555.lu for the override function.