msm: mdss: Display gamma control

TODO: confirm rgb channels, identify other tunables, cleanup,
apply values without switching screen (off and) on.

sysfs: /sys/devices/qcom,mdss_dsi_jdi_command_ors.69/*

Signed-off-by: flar2 <asegaert@gmail.com>

Conflicts:
	drivers/video/msm/mdss/mdss_dsi_panel.c
 msm: mdss: Fix issues in gamma interface

Protect access to panel command struct by mutex,
this should help with ULPS stability during panel
on as well.  Also, remove the broken debug FS.

by myfluxi

Conflicts:
	drivers/video/msm/mdss/mdss_dsi_panel.c