nir: Add colorspace support to YUV lowering pass

This change adds support for BT709 and BT2020 colorspace to the YUV
lowering pass. The default remains BT601.

This change also fixes minor imprecision in the last digits of the BT601
offsets due to computation from rounded values when the math was
simplified.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6122>
2 files changed