drm/amd/display: Add support for sRGB EOTF in DEGAM block

drm/amd/display: Add support for sRGB EOTF in DEGAM block

Expose one 1D curve colorop with support for
DRM_COLOROP_1D_CURVE_SRGB_EOTF and program HW to perform
the sRGB transform when the colorop is not in bypass.

With this change the following IGT test passes:
kms_colorop --run plane-XR30-XR30-srgb_eotf

The color pipeline now consists of a single colorop:
1. 1D curve colorop w/ sRGB EOTF

Signed-off-by: Alex Hung <alex.hung@amd.com>
Co-developed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patch.msgid.link/20251115000237.3561250-29-alex.hung@amd.com