vo_gpu: hwdec_drmprime_drm: add hwdec ctx

This allows to use drm hwaccels that require a hwdevice.

Tested with v4l2request hwaccel and cedrus driver on an allwinner device
running mpv with --vo=gpu --gpu-context=drm --hwdec=drm.

1 files changed, 1 insertions, 1 deletions

diff --git a/wscript b/wscript
index a83abcbc12..93144f9edd 100644
--- a/wscript
+++ b/wscript
@@ -563,7 +563,7 @@ video_output_features = [
         'name': '--drm',
         'desc': 'DRM',
         'deps': 'vt.h',
-        'func': check_pkg_config('libdrm'),
+        'func': check_pkg_config('libdrm', '>= 2.4.74'),
     }, {
         'name': '--drmprime',
         'desc': 'DRM Prime ffmpeg support',