drm/i915/bios: Define VBT block 46 (Chromaticity For Narrow Gamut Panel) contents

Define the contents of VBT block 46 (Chromaticity For Narrow Gamut
Panel). One entry per panel.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240503122449.27266-29-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>