libdvbpsi: new package

libdvbpsi is a library used by vlc for decoding MPEG TS

[Thomas:
 - add missing Config.in comment about the thread dependency.]

Signed-off-by: Pieterjan Camerlynck <pieterjan.camerlynck@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>