Enable ISDN support using net-libs/libcapi

Packages describing “capi” as local USE flag

Package “capi” Flag Description
app-emulation/wine-vanilla Enable ISDN support using net-libs/libcapi
app-emulation/crossover-bin Enable ISDN support via CAPI
app-emulation/wine-staging Enable ISDN support using net-libs/libcapi
media-video/rav1e Build the C-API library and header file

All packages providing a “capi” USE flag (2)