drm/colorop: Add PQ 125 EOTF and its inverse

drm/colorop: Add PQ 125 EOTF and its inverse

The PQ function defines a mapping of code values to nits (cd/m^2).
The max code value maps to 10,000 nits.

Windows DWM's canonical composition color space (CCCS)  defaults
to composing SDR contents to 80 nits and uses a float value of
1.0 to represent this. For this reason AMD HW hard-codes a PQ
function that is scaled by 125, yielding 80 nit PQ values for
1.0 and 10,000 nits at 125.0.

This patch introduces this scaled PQ EOTF and its inverse as
1D curve types.

Reviewed-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Sebastian Wick <sebastian.wick@redhat.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patch.msgid.link/20251115000237.3561250-32-alex.hung@amd.com