[PATCH] Add clamping to QColorTransferGenericFunction

[PATCH] Add clamping to QColorTransferGenericFunction

This ensures that the inputs are within range for the use of these
function.

Depending on the values passed, they can trigger FE_INVALID errors
and thus NaN as return values.

This can happen for example when feeding an invalid ICC profile to
QColorSpace::fromIccProfile.

Credit to OSS-Fuzz

Fixes: QTBUG-137159
Origin: upstream, https://download.qt.io/official_releases/qt/6.8/CVE-2025-5992-qtbase-6.8.patch

Gbp-Pq: Name upstream_cve-2025-5992_input_range_qcolortransformation.diff