vaapi: fix libvo/vo_vaapi.c compilation

Quick fix. No hwaccel. No GL. EOSD seems half broken.
Only X11 backend. But it works!

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
vaapi: add image formats

Based on commit 8bd591b02a5084216171ec577190f3cfe1eccd01

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
vaapi: add configure options

Add libva autodetection but keep it disabled by default.
Use --enable-vaapi to build mplayer with libva support.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>