Hi your ebuild uses the obsolete kbuild system, please take a new(probably better working ebuild from the gentoo-de overlay: http://gentoo.de/viewcvs/gentoo-x86/media-tv/linuxtv-dvb/ or use the patch that I attached
Created attachment 42337 [details, diff] linuxdvb.diff
Created attachment 42338 [details] linuxtv-dvb-1.1.1.ebuild
commited -r1 which uses kernel-mod
noone reopened it so i close the bug