[gst-vaapi][regression][vp9 10bit decode] all smoke test cases of vp9 10bit decode failed on gst-vaapi+i965 video driver

Platform: KBL Arch: x86_64 Kernel: 4.18.0+ libva commit 0dc70068e49f9538fbd03f2f0aa1e56a91e986e7

intel-vaapi-driver: commit 881e67a49b14631cb24a3880a28af9e5e5bacb96 gstreamer master branch 763d01f43755175410ca10f4c7b3af50c0cbc61e repo: https://gitlab.freedesktop.org/gstreamer/gstreamer.git

gst-plugins-base commit a6afa8881254e4104cbb7995e9bf5f952d1a46d3

repo: https://gitlab.freedesktop.org/gstreamer/gst-plugins-base.git gst-vaapi master branch bc8ddef9 repo: https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi.git

Reproduce Steps

1.build env as above 2.gst-launch-1.0 -vf filesrc location=./test_10bit.ivf ! ivfparse ! vaapivp9dec ! videoconvert ! video/x-raw,format=P010_10LE ! checksumsink2 file-checksum=false qos=false frame-checksum=false plane-checksum=false dump-output=true dump-location=./test_P010.yuv 3. gst_md5=bcf6191c8a9e6adbd707786f0a20e1b6 ref_md5=5c1e7ea1ee82f761f2f901414ef7d903 the ref_md5 can be got vai ffmpeg-soft/libyami, and some other test tools

Expected Result

the md5 of all cases match with reference