msm: mdss: Add gamma correction support in mdp3

Add gamma correction support in mdp3 driver via
MSMFB_MDP_PP ioctl. The ioctl has been extended to
program luts corresponding to histogram based
outputs and gamma correction based on flag.

The gain corresponding to gamma correction and
the histogram based output are combined in driver
and applied to hardware.

Change-Id: Ie875b4a9f4f4c752ad9a811ad68aff1c5110d57b
Signed-off-by: Krishna Chaitanya Parimi <cparimi@codeaurora.org>