drm/amd/display: add multiplier colorop

drm/amd/display: add multiplier colorop

This adds support for a multiplier. This multiplier is
programmed via the HDR Multiplier in DCN.

With this change the following IGT tests pass:
kms_colorop --run plane-XR30-XR30-multiply_125
kms_colorop --run plane-XR30-XR30-multiply_inv_125

The color pipeline now consists of the following colorops:
1. 1D curve colorop
2. 3x4 CTM
3. Multiplier
4. 1D curve colorop
5. 1D LUT
6. 1D curve colorop
7. 1D LUT

Signed-off-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patch.msgid.link/20251115000237.3561250-42-alex.hung@amd.com