drm/fourcc: map RGB24 chromas

The formats are little endian by default [1].

[1] https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/drm_fourcc.c

modules/video_output/drm/fourcc.c

@@ -175,6 +175,10 @@ static const struct {
     { DRM_FORMAT_RGBX8888, VLC_CODEC_XBGR },
     { DRM_FORMAT_BGRX8888, VLC_CODEC_XRGB },
 
+    /* Packed RGB24 formats */
+    { DRM_FORMAT_RGB888, VLC_CODEC_BGR24 },
+    { DRM_FORMAT_BGR888, VLC_CODEC_RGB24 },
+
     /* 8-bit RGB */
     { DRM_FORMAT_RGB332,   VLC_CODEC_RGB332 },
     { DRM_FORMAT_BGR233,   VLC_CODEC_BGR233 },