[vdr] VAAPI patches for FFmpeg & MPlayer

[Goga777]

These patches add VA API support to FFmpeg and MPlayer. 
HW video decode capabilities depend on the actual VA API implementation. Besides, from an MPlayer perspective, only full-offload (VLD) of the video is supported for the following codecs: 
MPEG-2
MPEG-4 ASP (DivX)
MPEG-4 AVC (H.264)
http://www.splitted-desktop.com/~gbeauchesne/mplayer-vaapi/
http://www.freedesktop.org/wiki/Software/vaapi