Requesting maintainer/committer access

Over the last few months, I've been actively hacking away at the rough diamond that libva is.

In terms of commits, as per `git shortlog -s -n origin/master | head -n10` I'm in the top 10, soon to be # 4.

```
422 Xiang, Haihao
267 Gwenole Beauchesne
254 Austin Yuan
63 Carl Zhang
57 Waldo Bastian
53 Lim Siew Hoon
52 Emil Velikov
34 Mark Thompson
28 Jonathan Bian
26 Sean V Kelley
```

Looking at the CONTRIBUTING.md - a commit of mine was picked as an example to follow. But I've also fixed a number of bugs, added features, improved the CI automation and discussed a number of issues.

So I would like to request maintainer/commit access to the repository. This will serve to merge PRs have have been reviewed yet left unmerged and close issues.

If the team (@XinfengZhang @dvrogozh) has particular requirements or requests, let me know.