remove tracing, fix piggy, tune build
    Tune deadline, readahead, ondemand, interactive.
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/*
msm: mdss: Apply commands values without switching screen (off and) on
msm: mdss: Remove tunable for command 32

Even slight changes look ugly or distort the screen.
msm: mdss: distinguish between Gamma RGB polarity Positive/Negative

Signed-off-by: Paul Reioux <reioux@gmail.com>
msm: mdss: Remove sysfs for unused commands
msm: mdss: Identify white point in sysfs
msm: mdss: Add safety check for user input

Leave more checks either to the control app or the user's intelligence.
Fix building.

Change-Id: I0d39796ab0c131bfce1f907abd44085d2b8a0160