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)

override for all samsung modes and profiles is enabled by default:
(echo 1 > /sys/class/mdnie/mdnie/enabled)

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

idea based on (mDNIe colour and brightness control) by AndreiLux.