Add lcms support (color management engine)

Packages describing “lcms” as local USE flag

Package “lcms” Flag Description
app-office/calligra Build colorengine plugins using media-libs/lcms
media-libs/libplacebo Add support for color management via media-libs/lcms
media-video/ffmpeg Enable ICC profile support via media-libs/lcms.

All packages providing a “lcms” USE flag (23)