I've slightly modified v4l-dvb-hg ebuild to use 'savedconfig' eclass. This allows user to specify which V4L/DVB kernel modules he needs and avoid wasting time building others.
Created attachment 187965 [details] Ebuild with savedconfig
Created attachment 187966 [details, diff] and diff for faster lookup
Created attachment 187997 [details] EAPI 2 ebuild.
Created attachment 187998 [details, diff] and diff for that one too
Already included in v4l-dvb-hg-0.1-r3