drm/amd/display: add CRTC gamma TF driver-specific property

drm/amd/display: add CRTC gamma TF driver-specific property

Add AMD pre-defined transfer function property to default DRM CRTC gamma
to convert to wire encoding with or without a user gamma LUT. There is
no post-blending regamma ROM for pre-defined TF. When setting Gamma TF
(!= Identity) and LUT at the same time, the color module will combine
the pre-defined TF and the custom LUT values into the LUT that's
actually programmed.

v2:
- enable CRTC prop in the end of driver-specific prop sequence
- define inverse EOTFs as supported regamma TFs
- reword driver-specific function doc to remove shaper/3D LUT

v3:
- spell out TF+LUT behavior in the commit and comments (Harry)

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Co-developed-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>