drm/amd/display: Don't use ROM for output TF if GAMMA_CS_TFM_1D

We can’t use hardcoded SRGB ROM for output TF if we have GAMMA_CS_TFM_1D
(unless we know 1D LUT is identity), so we never want to return here early.
We apply the LUT part of ColorTransform3x4 only in apply_lut_1d() which is
called near the end of that function.

Signed-off-by: Hugo Hu <hugo.hu@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>