gamma_control: add extensive control over the display gamma curve.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>

Conflicts:
	drivers/misc/Kconfig
	drivers/misc/Makefile
	drivers/video/msm/mipi_lgit.c
gamma_control: fix permissions for userspace apps.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>