Small cleanup and initial vdpau support for CedarX

* Silence portage warnings about repo_name and masters by adding metadata/layout.conf and profiles/repo_name
* Rename "xf86-video-sunxifb" to "xf86-video-fbturbo" to keep in line with upstream
* Initial vdpau support for CedarX from linux-sunxi/libvdpau-sunxi