mdnie : mdnie mode hijack (Yank555.lu)

* SysFs interface :
 *
 * /sys/class/mdnie/mdnie/hijack : 0 = disbaled / 1 = enabled
 *
 *    Enable / Disable hijacking of mdnie settings (default = disabled)
 *
 * /sys/class/mdnie/mdnie/sharpen : 0 = disbaled / 1 = enabled
 *
 *    Enable / Disable screen sharpness (default = enabled, stock Samsung Update 12+)
 *
 * /sys/class/mdnie/mdnie/black : -128 to +128
 *
 *    Global black level, will shift black RGB setting by this value (default = 0)
 *
 *    NB: Effectively applied values for black will never be below 0 nor above 255 !
 *
 *        So there is no use setting Black RGB to (0,0,0) and this to -10, the result
 *        will still be (0,0,0).
 *
 * /sys/class/mdnie/mdnie/{color}_red   : 0 to 255
 * /sys/class/mdnie/mdnie/{color}_green : 0 to 255
 * /sys/class/mdnie/mdnie/{color}_blue  : 0 to 255
 *
 *    Allows to set the RGB values for the base colors :
 *
 *      - red
 *      - green
 *      - blue
 *      - cyan
 *      - magenta
 *      - yellow
 *      - black
 *      - white
 *
 *    (default = Samsung's natural mode)