drm/amd/display: combined user regamma and OS GAMMA_CS_TFM_1D

[Why]
For user regamma we're missing this function call
to combine user regamma + OS for GAMMA_CS_TFM_1D type.

[How]
Applied 1D LUT in the mod_color_build_user_regamma.
And Set the regamma dirty as updateGamma.

Signed-off-by: Derek Lai <Derek.Lai@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>