drm/amd/display: add driver-specific property for plane degamma LUT

Hook up driver-specific atomic operations for managing AMD color
properties. Create AMD driver-specific color management properties
and attach them according to HW capabilities defined by `struct
dc_color_caps`.

First add plane degamma LUT properties that means user-blob and its
size. We will add more plane color properties in the next patches. In
addition, we define AMD_PRIVATE_COLOR to guard these driver-specific
plane properties.

Plane degamma can be used to linearize input space for arithmetical
operations that are more accurate when applied in linear color.

v2:
- update degamma LUT prop description
- move private color operations from amdgpu_display to amdgpu_dm_color

v5:
- get degamma blob correctly (Joshua)

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>